JP4286800B2 - Advance device for cold start of engine eccentric cam type mechanical timer - Google Patents

Description

  The present invention relates to an advance device for starting a cold engine of an eccentric cam type mechanical timer of an engine.

[Prerequisite configuration]
As shown in FIG. 3 (present invention) or FIG. 7 (prior art), for example, the advance angle device at the time of cold start of the eccentric cam type mechanical timer of the engine of the present invention is intended for the one having the following premise configuration. To do.

  FIG. 3 shows Embodiment 1 of the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine of the present invention. 3A is a vertical right side view of the eccentric cam type mechanical timer, FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A, and FIG. 3C is C of FIG. 3A. FIG.

  FIG. 7 shows an advance device at the time of cold start of the eccentric cam type mechanical timer of the engine of the prior art 1. FIG. 7A is a longitudinal left side view of the eccentric cam type mechanical timer, and is a cross-sectional view taken along line AA in FIG. 7B. FIG. 7B is a longitudinal front view of the central portion of FIG.

An output wheel (2) is arranged on one side of the input wheel (1) constituting the eccentric cam type mechanical timer of the engine, and a pair of centrifugal weights (3) (3) is arranged on the other side.
An eccentric cam type advance mechanism (4) is provided over the input wheel (1) and the output wheel (2). The eccentric cam type advance mechanism (4) is operated by an unbalanced force between the centrifugal force of the pair of centrifugal weights (3) and (3) and the tension to the centripetal side of the weight return spring (5) made of a compression coil spring. Thus, the output wheel (2) is configured to advance and operate with respect to the input wheel (1).

  The pair of centrifugal weights (3) and (3) are driven to advance in the centrifugal direction by a starting advance spring (6) made of a compression coil spring. The advance drive is released against the tension of the starting advance spring (6) by the extension operation when the temperature is sensed on the high temperature side.

  When the engine is cold-started, as shown in FIG. 4 (A), the starting advance angle canceling temperature sensing means (7) is contracted by the low temperature side temperature sensing, and the tension of the starting advance angle spring (6) is reduced. The pair of centrifugal weights (3) and (3) are configured to be expanded to the advance limit position (Lc) at the time of cold start.

  When the engine is warm, as shown in FIG. 4B, the starting advance angle release temperature sensing means (7) is extended by the high temperature side temperature sensing, and the start advance angle spring (6) is contracted. Thus, the starting advance spring (6) is configured to release the pair of centrifugal weights (3) (3) from being pushed and expanded to the cold start starting advance limit position (Lc).

[Conventional technology]
In the above premise structure, as a structure for combining the starting advance spring (6) and the start advance angle canceling temperature-sensing operating means (7), there is the prior art shown in FIG.
(Japanese Patent Laid-Open No. 3-11131)

  FIG. 7 shows an advance device at the time of cold start of the eccentric cam type mechanical timer of the prior art engine. FIG. 7A is a longitudinal left side view of the eccentric cam type mechanical timer, and is a cross-sectional view taken along line AA in FIG. 7B. FIG. 7B is a longitudinal front view of the central portion of FIG.

  The temperature advancement actuating means (7) for releasing the starting advance angle comprises a wax-enclosed type temperature sensitive actuator (50). A conical hole cam surface (51) is formed in the front half of the inner peripheral surface (53) of the pair of centrifugal weights (3) and (3). By pressing the conical cam (52) against the conical hole cam surface (51) with the tension of the starting advance spring (6), the centrifugal weights (3) and (3) are advanced at the cold start advance limit position (Lc). It is configured to spread out.

[Problems of conventional technology]
The above prior art has the following problems.
The conical cam (52) and the conical hole cam surface (51) slide during the transmission of the force between the starting advance spring (6) and the centrifugal weights (3) and (3), resulting in friction loss. There are the following problems 1 and 2 and 3 as much as they occur.

Problem 1: The control accuracy of the starting advance angle at the time of engine cold start decreases.
Problem 2: The temperature sensitive actuator (50) and the starting advance spring (6) require large capacity and small size.

  Problem 3: The conical cam (52) and the conical hole cam surface (51) interposed in the force transmission part from the starting advance spring (6) to the centrifugal weight (3) (3) are worn by sliding friction. Therefore, durability is reduced.

Japanese Patent Laid-Open No. 3-11131

An object of the present invention is to do as follows.
[I]. The amount of friction loss is eliminated during the transmission of the force between the spring for starting advance angle and both centrifugal weights. The advance angle spring and the start angle release temperature-sensing operation means can be reduced in size and size. 3: The durability of the force transmission portion from the start angle advance spring to the centrifugal weight is improved.

[B]. The length in the direction of the rotational axis of the centrifugal weight is shortened by arranging the start advance angle releasing shape memory spring and the start advance angle spring concentrically with respect to the weight return spring.
[C]. Both centrifugal weights are greatly expanded to the cold start advance angle limit position (Lc) required when starting the engine cold, and the start angle is fully actuated to start the engine reliably and powerfully. During engine operation, the advance operation between the two centrifugal weights is restricted to the advance angle limit position (Lw) during engine operation, thereby increasing the amount of NOx and combustion noise generated when the advance angle is excessive. Resolving these problems is compatible.

[D]. It solves both the problem that the advance angle is excessive when the engine is cold-started, and that the start angle advance spring has a high tension accuracy and can be used at a low cost that is not required.
[E]. Eliminates the problem of excessive advance angle during high-speed engine operation.

[F]. The total length of the eccentric cam type mechanical timer is shortened by reducing the maximum outer diameter of the weight return spring, the spring for starting advancement, and the shape memory spring for releasing the starting advancement and shortening the length of the centrifugal weight. .
[G]. The starting advance angle release shape memory spring and the starting advance spring reduce the rate of change of the spring tension with respect to the amount of spring expansion and contraction, so that the control accuracy of the starting advance angle at the time of cold start of the eccentric cam type mechanical timer is reduced. To increase.

[Chi]. In addition to improving the control accuracy of the starting advance angle at the time of cold start of the eccentric cam type mechanical timer, the durability of the start advance spring and the start advance release shape memory spring is improved.
[Li]. The pair of cold start advancement restricting bodies and engine operation advancement restricting bodies are configured with only one part number, in which a pair of advance restriction restricting holes are formed in one advance restriction plate. To be able to do with simple things.
[Nu]. Each of the pair of advance angle limiters utilizes a pair of each eccentric input pin for advancing the eccentric cam type advance mechanism, and is configured to the other end of each eccentric input pin. Simplify the high-precision mounting structure.

[Le]. The configuration of the advance angle limiting switching transmission device is a simple configuration in which a pair of driven holes formed in the advance angle limiting plate and a pair of main driving pins interlocked with the shape memory spring for starting advance angle release are simply engaged. Just do things.
[Wo]. The configuration for accurately transmitting the temperature-sensitive expansion / contraction operation of the advance memory for releasing the advance angle to the main drive pin is achieved by utilizing a transmission cylinder accurately interlocking with the start memory for releasing the advance angle. It can be done with a simple one with the main drive pin fixedly protruding from the outer casing of the transmission cylinder.

  In order to solve the above-described problems, the advance angle device at the time of cold start of the eccentric cam type mechanical timer of the engine according to the present invention is, for example, as shown in FIGS. The following characteristic configuration is added as a configuration for ensuring a proper structure for each advance angle limit value at the time of cold start and engine operation, and a combination structure of a spring and a temperature-sensitive operation means.

  1 to 6 show Embodiment 1 of an advance device at the time of cold start of an eccentric cam type mechanical timer of an engine of the present invention. FIG. 1 shows a centrifugal weight of an eccentric cam type mechanical timer in which a weight returning spring, a spring for starting advancement, and a temperature sensitive operating spring are incorporated. 1A is a cross-sectional front view taken along line AA of FIG. 1B, FIG. 1B is a plan view, FIG. 1C is a left side view, and FIG. 1D is FIG. It is the DD sectional view taken on the line. 1E is a view taken in the direction of arrow E in FIG. 1B, showing a front view of the advance angle limiting device 40, and FIG. 1F is a sectional view taken along line FF in FIG. is there.

FIG. 2 is a vertical right side view of a drive unit for a fuel injection pump of a water-cooled vertical diesel engine. 3A is a vertical right side view of the eccentric cam type mechanical timer, FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A, and FIG. 3C is C of FIG. 3A. FIG.
FIG. 4 is an enlarged view of a portion IV in FIG. FIG. 4A shows the contraction operation state of the shape memory spring for releasing the starting advance angle when the temperature is sensed on the low temperature side. FIG. 4B shows an extension operation state at the time of high-temperature temperature sensing of the shape memory spring for starting advance angle cancellation.

  FIG. 5 is a front view of the advance angle limiting device 40 and corresponds to FIG. FIG. 5A shows the advance angle limited state when the engine is cold start, and FIG. 5B shows the advance angle limited state during engine operation.

  FIG. 6 is an advance operation characteristic curve diagram with respect to the engine rotation speed of both centrifugal weights. FIG. 6A is an advance operation characteristic curve diagram when the engine is cold-started, and shows the operation characteristic in the state of FIG. FIG. 6 (B) is an advance operation characteristic curve diagram during the operation of the engine, and shows the operation characteristic in the state of FIG. 5 (B).

The invention of claim 1. See FIGS.
The starting advance angle canceling temperature-sensitive operating means (7) is constituted by a starting advance angle canceling shape memory spring (8) made of a shape memory alloy material. The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are positioned between the pair of centrifugal weights (3), (3), and the weight return spring ( 5) Concentrically with respect to 5).

  An advance limit device (40) is attached to the pair of centrifugal weights (3) (3). This advance angle limiting device (40) includes at least a pair of cold start start angle limiters (41) (41), a pair of engine operation advance angle limiters (42) (42), and an advance angle limit switching transmission. The device (43) (43) is provided.

  The pair of cold start starting advancement restricting bodies (41) and (41) are used to determine the amount of advancement (Θ) that the pair of centrifugal weights (3) and (3) open in the centrifugal direction. A pair of centrifugal weights (3) and (3) are received so as to be forcibly limited to (Lc).

The pair of engine operation advance angle limiting bodies (42), (42) is configured to force a pair of centrifugal weights (Θ) to forcibly limit the advance amount (Θ) to the engine operation advance angle limiting position (Lw). 3) (3) Configure to receive each other.
The cold start start advance limit position (Lc) is set to a value larger than the engine operation advance advance limit position (Lw).

  The pair of cold start start angle restricting bodies (41) and (41) and the pair of engine operation advance angle restricting bodies (42) and (42) are advanced relative to the pair of centrifugal weights (3) and (3). It is possible to selectively switch between an angle limit position and an advance angle limit release position, and this switching operation is canceled via the advance angle limit switching transmission device (43) (43). It is configured to be interlocked with the shape memory springs (8) and (8).

  The shape memory springs (8) and (8) for releasing the starting advance angle are in a state of being contracted by the low temperature side temperature sensing, while on the other hand, the pair of centrifugal weights (3 ) (3) is expanded to the cold start start advance limit position (Lc), and on the other hand, the advance limit restricting body during engine operation (43) (43) is provided via the advance limit changeover transmission (43) (43). 42) and (42) are retracted to the advance angle restriction release position, and the advance angle restriction bodies (41) and (41) at the time of cold start are put into the advance angle restriction position.

  On the other hand, the shape advance springs 8 and 8 for releasing the starting advance angle contract the starting advance springs 6 and 6 on the other hand in a state where the extension memory is operated by the high temperature side temperature sensing. The starting advance spring (6) (6) releases the pair of centrifugal weights (3) and (3) from being pushed and expanded to the cold start starting advance limit position (Lc). Via the limit switching transmission device (43) (43), the cold start starting advancement restricting body (41) (41) is retracted to the advance limit restricting position and the engine operating advancement restricting body (42 ) (42) is configured to enter the advance limit position.

O Invention of claim 2. See FIG. 1 and FIG.
The invention of claim 2 is characterized in that, in the invention of claim 1, the following characteristic configuration is added.

  Of the pair of centrifugal weights (3) and (3), one of the centrifugal weights (3A) (3B) is provided with a weight return spring (5), whereas the other centrifugal weight (3B) ) (3A) is provided with a starting advance spring (6) and a starting advance release shape memory spring (8).

The invention of claim 3. See FIG. 1 and FIG.
The invention of claim 3 is characterized in that, in the invention of claim 2, the following characteristic configuration is added.

  The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are configured to be inserted into and out of each other.

The invention of claim 4. See FIG. 1 and FIG.
The invention of claim 4 is characterized in that, in the invention of claim 3 described above, the following characteristic configuration is added.

  A transmission cylinder (9) is inserted between the start-advance-releasing shape memory spring (8) and the start-advance spring (6) that are inserted and fitted to each other. The outer rod (10) is continuously extended to the centrifugal side from one end of the transmission cylinder (9), whereas the inner rod (11) is continuously extended to the centripetal side from the other end of the cylinder.

  The other centrifugal weight (3B) (3A) of the pair of centrifugal weights (3), (3) is made to receive the spring base short part (12) of the starting advance spring (6). A spring tip (13) of the starting advance spring (6) is configured to press the one centrifugal weight (3A) (3B) to the centrifugal side via the outer rod (10).

  The other centrifugal weight (3B) (3A) receives the spring base end (15) of the starting advance angle release shape memory spring (8) via the weight opening / closing guide shaft (14), and this starting advance angle The spring tip (16) of the release shape memory spring (8) compresses the starting advance spring (6) through the inner rod (11), transmission cylinder (9), and outer rod (10) in this order. It is configured to repress to the side to be made.

The invention of claim 5. See FIG. 1 and FIG.
The invention of claim 5 is characterized in that, in the invention of claim 1, 2, 3 or 4, the following characteristic configuration is added.

An advance limit plate (44) is provided on the lateral side of the pair of centrifugal weights (3) (3). The advance limit plate (44) is pivotally supported so as to be reciprocally rotatable about the rotation axis of the centrifugal weight (3) (3).
A pair of advance angle limiting communication holes (45) and (45) are formed in the advance angle limiting plate (44). Each of the pair of advance angle limiting communication holes (45) (45) includes a pair of each of the cold start starting advance angle limiting slots (46) (46) and a pair of each engine operating advance angle limiting slot ( 47) and (47) are arranged side by side in the rotation direction of the centrifugal weights (3) and (3).

  The pair of cooler start-up advance limiters (41) (41) are formed by the respective centrifugal side peripheral wall portions of the pair of cooler start-up advance restriction limiting long holes (46, 46). The pair of engine operation advance angle limiting bodies (42) and (42) are formed by the respective centrifugal side peripheral wall portions of the pair of engine operation advance angle limiting elongated holes (47) and (47).

  A pair of advance angle limiters (48) and (48) are fixedly projected from the lateral sides of the pair of centrifugal weights (3) and (3). Each of the pair of advance angle restrictors (48), (48) is engaged with each of the pair of advance angle restricting communication holes (45), (45), and each of the pair of advance angle restrictors (41) ) (41) and a pair of advance limiters (42) and (42) during operation of each engine, which are inserted into the advance limit position, and can be received.

The invention of claim 6. See FIG. 1, FIG. 3 and FIG.
The invention of claim 6 is characterized in that, in the invention of claim 5, the following characteristic configuration is added.

  The input wheel (1) constituting the eccentric cam type mechanical timer of the engine is arranged on one lateral side of the pair of centrifugal weights (3) and (3), and the advance limit plate (44) is arranged on the other side. ). A pair of eccentric input pins (28), (28) for advancing the eccentric cam type advance mechanism (4) is penetrated laterally and fixed to the pair of centrifugal weights (3) (3). .

  Of the pair of eccentric input pins (28), (28), the other pair of eccentric input pins (49) (49) projecting outward from the other lateral sides of the centrifugal weights (3) (3). Each advance angle limiter (48) (48) is configured.

The invention of claim 7. See FIG. 1 and FIG.
The invention of claim 7 is characterized in that, in the invention of claim 5 or 6, the following characteristic configuration is added.

  The advance angle limiting switching transmission device (43) includes at least a pair of driven holes (38) and (38) and a pair of main driving pins (39) and (39). The pair of driven holes (38) and (38) are formed in the advance limit plate (44). The pair of main driving pins (39) and (39) are engaged with the pair of driven holes (38) and (38) and interlocked with the shape memory springs (8) and (8) for releasing the starting advance angle.

  Based on the temperature sensitive expansion / contraction operation of the starting advance angle release shape memory springs (8) and (8), the advance angle is restricted from the pair of main drive pins (39) and (39) through the pair of driven holes (38) and (38). Through the transmission to the plate (44), one of the pair of cold start start advancement restricting bodies (41) (41) and the engine operation advancement restricting bodies (42) (42) is set to the advance advance restricting position. It is characterized in that it is configured to receive the pair of advance angle limiters (48) and (48) with the input one.

The invention of claim 8. See FIG. 1, FIG. 4 and FIG.
The invention of claim 8 is characterized in that in the invention of claim 7 subordinate to claim 4, the following characteristic configuration is added.

  The outer casing (10) of the transmission cylinder (9) (9) inserted between the starting advance angle release shape memory spring (8) (8) and the starting advance spring (6) (6). From (10), the main driving pins (39) and (39) are fixedly projected to the advance angle limiting plate (44) side and engaged with the driven holes (38) and (38).

  The advance device at the time of cold start of the eccentric cam type mechanical timer of the engine of the present invention has the following effects.

The invention of claim 1. See FIGS.
[Effect a. As much as there is no friction loss in the middle of the transmission of force between the starting advance spring (6) and the centrifugal weights (3) (3). The angle control accuracy is improved. Effect 2: The start advance spring (6) and the start advance release shape memory spring (8) can be reduced in capacity and effect. Effect 3: Start advance spring (6) ) To the centrifugal weights (3) and (3) are improved in durability. ]

The invention of claim 1 has the following characteristic configuration.
The starting advance angle canceling temperature-sensitive operating means (7) is constituted by a starting advance angle canceling shape memory spring (8) made of a shape memory alloy material.
The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are positioned between the pair of centrifugal weights (3), (3), and the weight return spring ( Concentric with respect to 5).

  From this characteristic configuration, when the engine is cold-started, as shown in FIG. 4A, the start-advance-releasing shape memory spring (8) is contracted and the tension of the start-advance spring (6) is applied. The pair of centrifugal weights (3) and (3) are expanded to the advance limit position (Lc) at the time of cold start, and, as illustrated in FIGS. 1 and 3, through the advance mechanism (4), the fuel injection pump ( 19) The fuel injection timing is advanced to the advance position for cold start.

  At this time, since the spring for advancing angle (6) is pressed directly against the centrifugal weights (3) and (3) in the centrifugal direction, it is possible to eliminate friction loss during the transmission of the force. The following effects 1 and 2 and 3 could be achieved as much as this friction loss was eliminated.

Effect 1: The control accuracy of the starting advance angle at the time of cold start of the engine is improved by the amount that the friction loss during the transmission of the force is eliminated.
Effect 2: The starting advance angle spring (6) and the starting advance angle release shape memory spring (8) can be reduced in capacity and size as much as the friction loss during the transmission of the force is eliminated. .

  Effect 3: The transmission portion of the force from the starting advance spring (6) to the centrifugal weight (3) (3) is less worn and the durability is improved as much as there is no friction loss.

  [Effect b. The shape advance spring for starting advance angle release (8) and the spring for start advance angle (6) are not displaced in the direction of the rotational axis of the centrifugal weight (3) (3) with respect to the weight return spring (5). Therefore, the length of the centrifugal weights (3) and (3) is shortened as much as possible, thereby contributing to the shortening of the total length of the eccentric cam type mechanical timer. ]

  As illustrated in FIGS. 1 and 4, the starting advance angle release shape memory spring (8) and the starting advance angle spring (6) are separated from the weight return spring (5) by the centrifugal weight (3) (3 ) It is arranged concentrically at the position between them, and the direction of the rotational axis of the centrifugal weights (3) and (3) is the same as the position of the centrifugal weights (3) and (3). This can contribute to shortening the overall length of the eccentric cam type mechanical timer.

[Effect C. Effect 4: Both the centrifugal weights (3) and (3) are sufficiently expanded in the centrifugal direction to the cold start advancement limit position (Lc) required for engine cold start, and fully start advance operation So, make sure the engine is cold and start
Effect 5: During engine operation, the advance operation between the centrifugal weights (3) and (3) is limited to the advance limit position (Lw) during engine operation, eliminating excessive advance during high-speed rotation. Thus, it is possible to reconcile problems such as an increase in the amount of NOx and combustion noise generated when the advance angle is excessive. ]

The invention of claim 1 has the following characteristic configuration.
An advance limit device (40) is attached to the pair of centrifugal weights (3) (3). This advance angle limiting device (40) includes at least a pair of cold start start angle limiters (41) (41), a pair of engine operation advance angle limiters (42) (42), and an advance angle limit switching transmission. The device (43) (43) is provided.

  The pair of cold start starting advancement restricting bodies (41) and (41) are used to determine the amount of advancement (Θ) that the pair of centrifugal weights (3) and (3) open in the centrifugal direction. A pair of centrifugal weights (3) and (3) are received so as to be forcibly limited to (Lc).

The pair of engine operation advance angle limiting bodies (42), (42) is configured to force a pair of centrifugal weights (Θ) to forcibly limit the advance amount (Θ) to the engine operation advance angle limiting position (Lw). 3) (3) Configure to receive each other.
The cold start start advance limit position (Lc) is set to a value larger than the engine operation advance advance limit position (Lw).

  The pair of cold start start angle restricting bodies (41) and (41) and the pair of engine operation advance angle restricting bodies (42) and (42) are advanced relative to the pair of centrifugal weights (3) and (3). It is possible to selectively switch between an angle limit position and an advance angle limit release position, and this switching operation is canceled via the advance angle limit switching transmission device (43) (43). It is configured to be interlocked with the shape memory springs (8) and (8).

  The shape memory springs (8) and (8) for releasing the starting advance angle are in a state of being contracted by the low temperature side temperature sensing, while on the other hand, the pair of centrifugal weights (3 ) (3) is expanded to the cold start start advance limit position (Lc), and on the other hand, the advance limit restricting body during engine operation (43) (43) is provided via the advance limit changeover transmission (43) (43). 42) and (42) are retracted to the advance angle restriction release position, and the advance angle restriction bodies (41) and (41) at the time of cold start are put into the advance angle restriction position.

  On the other hand, the shape advance springs 8 and 8 for releasing the starting advance angle contract the starting advance springs 6 and 6 on the other hand in a state where the extension memory is operated by the high temperature side temperature sensing. The starting advance spring (6) (6) releases the pair of centrifugal weights (3) and (3) from being pushed and expanded to the cold start starting advance limit position (Lc). Via the limit switching transmission device (43) (43), the cold start starting advancement restricting body (41) (41) is retracted to the advance limit restricting position and the engine operating advancement restricting body (42 ) (42) is inserted into the advance limit position.

From this characteristic configuration, the following effects 4 and 5 are produced.
{Effect 4: Both centrifugal weights (3) and (3) are sufficiently expanded in the centrifugal direction to the cold start advance limit position (Lc), which is necessary when starting the engine cold, and the start angle is sufficiently wide. Because it works, make sure that the engine is cold and cold. }

At the time of cold start when the engine is not yet warmed, the engine operates as shown in FIGS. 4 (A), 5 (A), and 6 (A).
The shape memory springs (8), (8) for releasing the starting advance angle are in a contracted state due to the low temperature side temperature sensing, and on the other hand, a pair of centrifugal weights (3) with the tension of the starting advance springs (6, 6). (3) is set in a state where it is expanded to the advance limit position (Lc) at the time of cold start, and on the other hand, the advance limit body (42) at the time of engine operation is transmitted via the advance limit switching transmission device (43) (43). ) (42) is retracted to the advance angle limit release position, and the advance limiter bodies (41) (41) at the time of cold start are put into the advance angle limit position.

  As a result, both the centrifugal weights (3) and (3) are freely expanded in the centrifugal direction to the cold start advance limit position (Lc) required when starting the engine cold, and the start advance operation is sufficiently performed. Therefore, start the engine coldly and reliably.

  {Effect 5: When the engine is in operation, the advance operation between the centrifugal weights (3) and (3) is limited to the advance limit position (Lw) during engine operation. Eliminate problems such as increased NOx and combustion noise generated when the advance angle is excessive. }

At the time of restarting the warmer when the engine is warmed and during operation, the engine operates as shown in FIGS. 4 (B), 5 (B), and 6 (B).
The shape advance springs 8 and 8 for releasing the start angle are in an extended state due to the high temperature side temperature sensing, and on the other hand, the start angle springs 6 and 6 are contracted and used for this start angle. The springs (6) and (6) are released from pushing the pair of centrifugal weights (3) and (3) to the advance limit position (Lc) at the time of cold start, and on the other hand, the advance limit change switching transmission device ( 43) (43), the cold start start angle limiter (41) (41) is retracted to the advance limit release position and the engine operation advance angle limiter (42) (42) is advanced. Put it in the corner limit position.

  For this reason, at the time of engine warm-up restart and during operation, the advance operation between the centrifugal weights (3) and (3) is smaller than the advance limit limit position (Lc) at the time of cold start. Since it is limited to the advance angle limit position (Lw), it is possible to eliminate the excessive advance angle at the time of high-speed rotation and to solve problems such as an increase in the amount of NOx and combustion noise generated when this advance angle is excessive. it can.

As described above, the effect 4: Both the centrifugal weights (3) and (3) are sufficiently expanded in the centrifugal direction to the cold start advance limit position (Lc) necessary for the cold start of the engine. Since the start angle is operated, the engine is surely and powerfully started cold,
Effect 5: During engine operation, the advance operation between the centrifugal weights (3) and (3) is limited to the advance limit position (Lw) during engine operation, eliminating excessive advance during high-speed rotation. Thus, it is possible to reconcile problems such as an increase in the amount of NOx and combustion noise generated when the advance angle is excessive.

  [Effects d. To solve the problem that the advance angle is excessive when starting the engine cold, and to use the start angle advance spring (6) (6) with high tension accuracy and low cost that is not required. Can do. ]

At the time of cold start when the engine is not yet warmed, the engine operates as shown in FIGS. 4 (A), 5 (A), and 6 (A).
At the time of engine cold start, the shape advance springs 8 and 8 for releasing the start angle are in a contracted state due to the low temperature side temperature sensing, while the pair of springs 6 and 6 are tensioned by the start angle advance springs 6 and 6. The centrifugal weights (3) and (3) are pushed and expanded to the advance angle limit position (Lc) at the time of cold start, and on the other hand, when the engine is operated via the advance angle limit switching transmission device (43) (43). The advance limiters (42) and (42) are retracted to the advance limit release position, and the advance limiters (41) and (41) at the time of cold start are put into the advance limit position.

  When the advanced angle limiter (41) (41) is inserted into the advance limit position and the advanced angle limiter (48) (48) is received by the cold starter, both centrifugal weights (3) (3) Since the advance angle limit position (Lc) at the time of cold start is accurately received, the problem that the advance angle is excessively advanced at the time of cold start of the engine can be solved.

  Moreover, the tension of the starting advance springs (6) and (6) increases the tension balance with the respective tensions of the starting advance angle releasing shape memory springs (8) and (8) and the weight return springs (5) and (5). Since it is not necessary to set the accuracy and it is only necessary to set a slightly higher tension, the start-advance springs (6) and (6) can be used at a low cost which does not require high tension accuracy.

  [Effect E. The problem that the advance angle is excessive during high-speed engine operation can be solved. ]

During high-speed operation of the engine, the engine operates as shown in FIGS. 4 (B), 5 (B) and 6 (B).
During high-speed operation of the engine, the starting advance angle release shape memory springs (8) and (8) are in an extended state due to the high temperature side temperature sensing, while the starting advance springs (6) and (6) are contracted. The starting advance spring (6) (6) releases the pair of centrifugal weights (3) and (3) from being pushed and expanded to the cold start starting advance limit position (Lc). Via the limit switching transmission device (43) (43), the cold start starting advancement restricting body (41) (41) is retracted to the advance limit restricting position and the engine operating advancement restricting body (42 ) (42) is put into the advance limit position.

  When the advanced angle restricting body (42) (42) at the time of engine operation put in this advanced angle restricting position is received by the advanced angle restricting body (48) (48), both centrifugal weights (3) (3) Can be accurately received at the advanced angle limit position (Lw) during engine operation, so that the problem of excessive advance of the angle during high speed operation of the engine can be solved.

O Invention of claim 2. See FIG. 1 and FIG.
In addition to [Effects A] to [Effect] of the invention of the above-mentioned Claim 1, the invention of Claim 2 has the following effects.

  [Effects. The length of the centrifugal weights (3) and (3) is reduced by the amount that the maximum outer diameter of the weight return spring (5), the starting advance spring (6), and the shape memory spring (8) for releasing the starting advance angle can be reduced. This contributes to shortening the overall length of the eccentric cam type mechanical timer. ]

The invention of claim 2 has the following characteristic configuration.
Of the pair of centrifugal weights (3) and (3), one of the centrifugal weights (3A) (3B) is provided with a weight return spring (5), whereas the other centrifugal weight (3B) ) (3A) is provided with a starting advance spring (6) and a starting advance release shape memory spring (8).

  Because of this characteristic configuration, the weight return spring (5), the starting advance spring (6), and the starting advance release shape memory spring (8) need only be inserted into and out of these three parts. To reduce the total length of the eccentric cam type mechanical timer, the length of the centrifugal weights (3) and (3) is further shortened by the amount that can reduce the maximum outer diameter of the spring (5) (6) (8). Can contribute.

The invention of claim 3. See FIG. 1 and FIG.
In addition to [Effects A] to [Effect] of the invention of the first aspect and [Effect] of the invention of the second aspect, the invention of the third aspect has the following effects.

  [Effects. The start advance angle release shape memory spring (8) and the start advance spring (6) have an eccentric cam type that reduces the rate of change of spring tension with respect to the amount of spring expansion and contraction by the amount that each spring length can be increased. Increase the control accuracy of the lead angle when starting the cold start of the mechanical timer. ]

Invention 3 has the following characteristic configuration.
The start-advance-releasing shape memory spring (8) and the start-advance spring (6) were inserted in and out of each other.

  Due to this characteristic configuration, the starting advance angle release shape memory spring (8) and the starting advance angle spring (6) are inserted into each other and inserted into each other, so that each spring (8 ) Increase the accuracy of control of the advance angle at the time of cold start of the eccentric cam type mechanical timer by reducing the rate of change of the spring tension with respect to the amount of spring expansion and contraction, as much as the spring length of (6) can be increased. Can do.

The invention of claim 4. See FIG. 1 and FIG.
In addition to [Effects A] to [Effect E] of the invention of Claim 1 above, [Effect F] of the invention of Claim 2 and [Effect G] of the invention of Claim 3, The following effects are obtained.

  [Effect H. The start advance angle spring (6) and the start advance angle release shape memory spring (8) can be accurately and stably balanced through the transmission cylinder (9). In addition, interference between the springs (6) and (8) is prevented by the transmission cylinder (9) to improve the control accuracy and stability of the advance angle at the time of cold start of the eccentric cam type mechanical timer. Prevents wear of the springs (6) and (8) to increase durability. ]

The invention of claim 4 has the following characteristic configuration.
A transmission cylinder (9) is inserted between the start-advance-releasing shape memory spring (8) and the start-advance spring (6) that are inserted and fitted to each other. The outer rod (10) is continuously extended to the centrifugal side from one end of the transmission cylinder (9), whereas the inner rod (11) is continuously extended to the centripetal side from the other end of the cylinder.

  The other centrifugal weight (3B) (3A) of the pair of centrifugal weights (3), (3) is made to receive the spring base short part (12) of the starting advance spring (6). A spring tip (13) of the starting advance spring (6) is configured to press the one centrifugal weight (3A) (3B) to the centrifugal side via the outer rod (10).

  The other centrifugal weight (3B) (3A) receives the spring base end (15) of the starting advance angle release shape memory spring (8) via the weight opening / closing guide shaft (14), and this starting advance angle The spring tip (16) of the release shape memory spring (8) compresses the starting advance spring (6) through the inner rod (11), transmission cylinder (9), and outer rod (10) in this order. It was configured to repress to the side to be made.

  From this characteristic configuration, the starting advance spring (6) and the starting advance release shape memory spring (8) are sequentially passed through the outer rod (10), transmission cylinder (9) and inner rod (11). It can be balanced and operated accurately and stably. In addition, since the interference between the springs (6) and (8) can be prevented by the transmission cylinder (9), the control accuracy and stability of the advance angle at the time of cold start of the eccentric cam type mechanical timer are improved. In addition, the wear of both springs (6) and (8) can be prevented and the durability can be enhanced.

The invention of claim 5. See FIG. 1 and FIG.
In addition to [Effects A] to [Effect E] of the above-mentioned invention of claim 1, the invention of claim 5 has the following effects.

  [Effects. A pair of cold start start angle restricting bodies (41) and (41) and an engine operation advance angle restricting body (42) and (42) are provided for a single advance angle restricting plate (44) and the pair of advance angle restricting bodies (44). A simple structure having only one part, in which the long holes (46) and (46) are formed, is sufficient. ]

The invention of claim 5 has the following characteristic configuration.
An advance limit plate (44) is provided on the lateral side of the pair of centrifugal weights (3) and (3), and this advance limit plate (44) is a fulcrum about the rotational axis of the centrifugal weights (3) and (3). It is pivotally supported as reciprocating rotation.

  A pair of advance angle limiting communication holes (45) and (45) are formed in the advance angle limiting plate (44). Each of the pair of advance angle limiting communication holes (45) (45) includes a pair of each of the cold start starting advance angle limiting slots (46) (46) and a pair of each engine operating advance angle limiting slot ( 47) and (47) are arranged side by side in the rotation direction of the centrifugal weights (3) and (3).

  The pair of cooler start-up advance limiters (41) (41) are formed by the respective centrifugal side peripheral wall portions of the pair of cooler start-up advance restriction limiting long holes (46, 46). The pair of engine operation advance angle limiting bodies (42) and (42) are formed by the respective centrifugal side peripheral wall portions of the pair of engine operation advance angle limiting elongated holes (47) and (47).

  A pair of advance angle limiters (48) and (48) are fixedly projected from the lateral sides of the pair of centrifugal weights (3) and (3). Each of the pair of advance angle restrictors (48), (48) is engaged with each of the pair of advance angle restricting communication holes (45), (45), and each of the pair of advance angle restrictors (41) ) (41) and a pair of advance limiters (42) and (42) at the time of operation of each engine are configured to be received by the one that is put into the advance limit position.

  From this characteristic configuration, the pair of cold start start advancement restricting bodies (41) (41) and the engine operation advancement restricting bodies (42) (42) are provided on a single advance advancement restricting plate (44). A simple structure having only one part number in which the pair of advance angle limiting long holes (46) and (46) is formed is sufficient, and the manufacturing cost can be reduced.

The invention of claim 6. See FIG. 1, FIG. 3 and FIG.
The invention of claim 6 has the following effects in addition to [Effects I] to [Effect E] of the invention of claim 1 and [Effects] of the invention of claim 5.

  [Effect Nu. Each of the pair of advance angle limiters (48) and (48) uses the eccentric input pins (28) and (28), and is configured by the other ends (49) and (49) of the eccentric input pins. A highly accurate attachment structure to each centrifugal weight (3) (3) is simplified. ]

The invention of claim 6 has the following characteristic configuration.
The input wheel (1) constituting the eccentric cam type mechanical timer of the engine is arranged on one lateral side of the pair of centrifugal weights (3) and (3), and the advance limit plate (44) is arranged on the other side. ). A pair of eccentric input pins (28), (28) for advancing the eccentric cam type advance mechanism (4) is penetrated laterally and fixed to the pair of centrifugal weights (3) (3). .
Of the pair of eccentric input pins (28), (28), the other pair of eccentric input pins (49) (49) projecting outward from the other lateral sides of the centrifugal weights (3) (3). Each advance angle limiter (48) (48) was constructed.

  From this characteristic configuration, each of the pair of advance angle limiters (48) and (48) uses the eccentric input pins (28) and (28), and the eccentric input pins at the other end portions (49) and (49). As much as the configuration, a highly accurate mounting structure to each centrifugal weight (3) (3) is simplified, and the manufacturing cost can be reduced.

The invention of claim 7. See FIG. 1 and FIG.
In addition to the [Effects A] to [Effect E] of the invention of the first aspect and the [Effect] of the invention of the fifth aspect, the invention of claim 7 has the following effects.

  [Effects. The advance angle limit switching transmission (43) is composed of a pair of driven holes (38) (38) formed in the advance limit plate (44) and a shape memory spring (8) (8) (8) ) And a pair of main driving pins (39) and (39) that are simply engaged with each other. ]

The invention of claim 7 has the following characteristic configuration.
The advance angle limiting switching transmission device (43) includes at least a pair of driven holes (38) and (38) and a pair of main driving pins (39) and (39). The pair of driven holes (38) and (38) are formed in the advance limit plate (44). The pair of main driving pins (39), (39) are engaged with the pair of driven holes (38), (38) and interlocked with the starting advance angle releasing shape memory springs (8), (8).

  Based on the temperature sensitive expansion / contraction operation of the starting advance angle release shape memory springs (8) and (8), the advance angle is restricted from the pair of main drive pins (39) and (39) through the pair of driven holes (38) and (38). Through the transmission to the plate (44), one of the pair of cold start start advancement restricting bodies (41) (41) and the engine operation advancement restricting bodies (42) (42) is set to the advance advance restricting position. The pair of propelled angle restrictors (48) and (48) are configured to receive the pair of propelled angle restrictors (48) and (48).

  From this characteristic configuration, the configuration of the advance angle limiting switching transmission device (43) includes a pair of driven holes (38) and (38) formed in the advance angle limiting plate (44) and a shape memory for starting advance angle cancellation. The pair of main driving pins (39) and (39) linked to the springs (8) and (8) can be simply engaged, and the manufacturing cost can be reduced.

The invention of claim 8. See FIG. 1, FIG. 4 and FIG.
The invention according to claim 8 is the [Effect A] to [Effect E] of the invention of Claim 1 above, [Effect H] of the invention of Claim 4, [Effect] of the invention of Claim 5, and Claims In addition to [Effect] of the seventh invention, the following effects can be obtained.

  [Effects. The configuration for accurately transmitting the temperature sensitive expansion / contraction operation of the starting advance angle release shape memory springs (8), (8) to the main drive pins (39) (39) is a shape memory spring for starting advance angle release ( 8) Utilizing the transmission cylinder (9) (9) precisely interlocking with (8), the outer cylinder (10) (10) of the transmission cylinder (9) (9) is connected to the main driving pin (39) (39 ) Is only required to stick and protrude. ]

The invention of claim 8 has the following characteristic configuration.
The outer casing (10) of the transmission cylinder (9) (9) inserted between the starting advance angle release shape memory spring (8) (8) and the starting advance spring (6) (6). From (10), the main driving pins (39) and (39) are fixedly projected to the advance angle limiting plate (44) side and engaged with the driven holes (38) and (38).

  From this characteristic configuration, the configuration for accurately transmitting the temperature sensitive expansion / contraction operation of the shape memory springs (8), (8) for releasing the starting advance angle to the main driving pins (39) (39) is the start advance angle. Using the transmission cylinders (9) and (9) accurately interlocking with the release shape memory springs (8) and (8), the main cylinder is driven from the outer rods (10) and (10) of the transmission cylinders (9) and (9). It is sufficient that the pins (39) and (39) are fixed and protruded, and the manufacturing cost can be reduced.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an advance angle device at the time of cold start of an eccentric cam type mechanical timer for an engine according to the present invention will be described with reference to the drawings.

Embodiment 1 Claims 1, 2, 3, 4, 5, 6, 7. See FIGS.
1 to 6 show Embodiment 1 of an advance device at the time of cold start of an eccentric cam type mechanical timer of an engine of the present invention. FIG. 1 shows a centrifugal weight of an eccentric cam type mechanical timer in which a weight returning spring, a spring for starting advancement, and a temperature sensitive operating spring are incorporated. 1A is a cross-sectional front view taken along line AA of FIG. 1B, FIG. 1B is a plan view, FIG. 1C is a left side view, and FIG. 1D is FIG. It is the DD sectional view taken on the line. 1E is a view taken in the direction of arrow E in FIG. 1B, showing a front view of the advance angle limiting device 40, and FIG. 1F is a sectional view taken along line FF in FIG. is there.

  FIG. 2 is a vertical right side view of a drive unit for a fuel injection pump of a water-cooled vertical diesel engine. 3A is a vertical right side view of the eccentric cam type mechanical timer, FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A, and FIG. 3C is C of FIG. FIG.

  FIG. 4 is an enlarged view of a portion IV in FIG. FIG. 4A shows the contraction operation state of the shape memory spring for releasing the starting advance angle when the temperature is sensed on the low temperature side. FIG. 4B shows an extension operation state at the time of high-temperature temperature sensing of the shape memory spring for starting advance angle cancellation.

  FIG. 5 is a front view of the advance angle limiting device 40 and corresponds to FIG. FIG. 5A shows the advance angle limited state when the engine is cold start, and FIG. 5B shows the advance angle limited state during engine operation.

  FIG. 6 is an advance operation characteristic curve diagram with respect to the engine rotation speed of both centrifugal weights. FIG. 6A is an advance operation characteristic curve diagram when the engine is cold-started, and shows the operation characteristic in the state of FIG. FIG. 6 (B) is an advance operation characteristic curve diagram during the operation of the engine, and shows the operation characteristic in the state of FIG. 5 (B).

  In FIG. 2, reference numeral (19) is a fuel injection pump, (20) is an eccentric cam type mechanical timer, (21) is a fuel injection cam gear, (22) is a timer input shaft, and (23) is a cylindrical fuel injection cam. Is the axis. The power of the engine crankshaft (not shown) is transmitted from the fuel injection cam gear (21) to the fuel injection camshaft (23) via the timer input shaft (22) and the eccentric cam type mechanical timer (20).

The eccentric cam type mechanical timer (20) is configured as follows.
As shown in FIGS. 1 and 3, an output wheel (2) is provided on one side of an input wheel (1) constituting an eccentric cam type mechanical timer of the engine, and a pair of centrifugal weights (3) ( 3) is arranged.

  An eccentric cam type advance mechanism (4) is provided over the input wheel (1) and the output wheel (2). The eccentric cam type advance mechanism (4) is operated by an unbalanced force between the centrifugal force of the pair of centrifugal weights (3) and (3) and the tension to the centripetal side of the weight return spring (5) made of a compression coil spring. Thus, the output wheel (2) is configured to advance and operate with respect to the input wheel (1).

  The pair of centrifugal weights (3) and (3) are driven to advance in the centrifugal direction by a starting advance spring (6) made of a compression coil spring. The advance drive is released against the tension of the starting advance spring (6) by the extension operation when the temperature is sensed on the high temperature side.

  When the engine is cold-started, as shown in FIG. 4 (A), the starting advance angle releasing temperature sensing means (7) is contracted by the low temperature side temperature sensing, and the tension of the starting advance angle spring (6) is applied. The pair of centrifugal weights (3) and (3) are configured to be expanded to the advance angle limiting position (Lc) at the time of cold start.

  When the engine is warm, as shown in FIG. 4 (B), the starting advance angle canceling temperature sensing means (7) is extended by the high temperature side temperature sensing and the starting advance angle spring (6) is contracted. The starting advance spring (6) is configured to release the pair of centrifugal weights (3) (3) from being pushed and expanded to the cold start starting advance limit position (Lc).

The eccentric cam type advance mechanism (4) is well known and is configured as follows.
As shown in FIG. 3, a large-diameter eccentric ring (25) and a small-diameter eccentric ring (27) are sequentially fitted in the input ring (1). A pair of large ring pivot support holes (24) are opened at two point-symmetrical eccentric positions of the input wheel (1).

  A pair of large-diameter eccentric rings (25) are fitted into the large-ring support holes (24), and are rotatably supported. Each small wheel pivot support hole (26) is opened at an eccentric position of each large diameter eccentric ring (25). A pair of small diameter eccentric rings (27) are fitted into the small wheel pivot support holes (26), and are rotatably supported.

  Each eccentric input pin (28) of each large-diameter eccentric ring (25) is connected by being fitted into each pair of centrifugal weights (3). Each eccentric output pin (29) of each small wheel eccentric wheel (27) is connected to the output wheel (2) by being fitted inside.

  The cylindrical shaft portion (41) of the input wheel (1) is fitted on the timer input shaft (22), fixed to the timer input shaft (22) with a nut (31), and rotated integrally with the key. It is connected. The output wheel (2) is externally fitted to the fuel injection cam shaft (23) and is connected so as to rotate integrally with a key.

  As shown in FIG. 1 and FIG. 4, the start-advance-releasing temperature-sensitive operating means (7) is constituted by a start-advance-releasing shape memory spring (8) made of a shape memory alloy material. The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are positioned between the pair of centrifugal weights (3), (3), and the weight return spring ( 5) Concentrically with respect to 5).

  As shown in FIGS. 1 to 3-6, an advance angle limiting device (40) is attached to the pair of centrifugal weights (3) (3). This advance angle limiting device (40) includes at least a pair of cold start start angle limiters (41) (41), a pair of engine operation advance angle limiters (42) (42), and an advance angle limit switching transmission. The device (43) (43) is provided.

  The pair of cold start starting advancement restricting bodies (41) and (41) are used to determine the amount of advancement (Θ) that the pair of centrifugal weights (3) and (3) open in the centrifugal direction. A pair of centrifugal weights (3) and (3) are received so as to be forcibly limited to (Lc).

  The pair of engine operation advance angle limiting bodies (42), (42) is configured to force a pair of centrifugal weights (Θ) to forcibly limit the advance amount (Θ) to the engine operation advance angle limiting position (Lw). 3) (3) Configure to receive each other. The cold start start advance limit position (Lc) is set to a value larger than the engine operation advance advance limit position (Lw).

  The pair of cold start start angle restricting bodies (41) and (41) and the pair of engine operation advance angle restricting bodies (42) and (42) are advanced relative to the pair of centrifugal weights (3) and (3). It is possible to selectively switch between an angle limit position and an advance angle limit release position, and this switching operation is canceled via the advance angle limit switching transmission device (43) (43). It is configured to be interlocked with the shape memory springs (8) and (8).

  The shape memory springs (8) and (8) for releasing the starting advance angle are in a state of being contracted by the low temperature side temperature sensing, while on the other hand, the pair of centrifugal weights (3 ) (3) is expanded to the cold start start advance limit position (Lc), and on the other hand, the advance limit restricting body during engine operation (43) (43) is provided via the advance limit changeover transmission (43) (43). 42) and (42) are retracted to the advance angle restriction release position, and the advance angle restriction bodies (41) and (41) at the time of cold start are put into the advance angle restriction position.

  On the other hand, the shape advance springs 8 and 8 for releasing the starting advance angle contract the starting advance springs 6 and 6 on the other hand in a state where the extension memory is operated by the high temperature side temperature sensing. The starting advance spring (6) (6) releases the pair of centrifugal weights (3) and (3) from being pushed and expanded to the cold start starting advance limit position (Lc). Via the limit switching transmission device (43) (43), the cold start starting advancement restricting body (41) (41) is retracted to the advance limit restricting position and the engine operating advancement restricting body (42 ) (42) is inserted into the advance limit position.

  Of the pair of centrifugal weights (3) and (3), one of the centrifugal weights (3A) (3B) is provided with a weight return spring (5), whereas the other centrifugal weight (3B) ) (3A) includes a starting advance spring (6) and a starting advance release shape memory spring (8). The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are inserted in and out of each other.

  A transmission cylinder (9) is inserted between the start-advance-releasing shape memory spring (8) and the start-advance spring (6) that are inserted and fitted to each other. The outer rod (10) is continuously extended to the centrifugal side from one end of the transmission cylinder (9), whereas the inner rod (11) is continuously extended to the centripetal side from the other end of the cylinder.

  The other centrifugal weight (3B) (3A) of the pair of centrifugal weights (3), (3) is made to receive the spring base end (12) of the starting advance spring (6). A spring tip (13) of the starting advance spring (6) is configured to press the one centrifugal weight (3A) (3B) to the centrifugal side via the outer rod (10).

  The other centrifugal weight (3B) (3A) receives the spring base end (15) of the starting advance angle release shape memory spring (8) via the weight opening / closing guide shaft (14), and this starting advance angle The spring tip (16) of the release shape memory spring (8) compresses the starting advance spring (6) through the inner rod (11), transmission cylinder (9), and outer rod (10) in this order. It was configured to repress to the side to be made.

An advance limit plate (44) is provided on the lateral side of the pair of centrifugal weights (3) and (3), and this advance limit plate (44) is a fulcrum about the rotational axis of the centrifugal weights (3) and (3). It is pivotally supported as reciprocating rotation.
A pair of advance angle limiting communication holes (45) and (45) are formed in the advance angle limiting plate (44). Each of the pair of advance angle limiting communication holes (45) (45) includes a pair of each of the cold start starting advance angle limiting slots (46) (46) and a pair of each engine operating advance angle limiting slot ( 47) and (47) are arranged in communication with each other in the rotational direction of the centrifugal weights (3) and (3).

The pair of cooler start-up advance limiters (41) (41) are formed by the respective centrifugal side peripheral wall portions of the pair of cooler start-up advance restriction limiting long holes (46, 46). The pair of engine operation advance angle limiting bodies (42) and (42) are formed by the respective centrifugal side peripheral wall portions of the pair of engine operation advance angle limiting elongated holes (47) and (47).
A pair of advance angle limiters (48) and (48) are fixedly projected from the lateral sides of the pair of centrifugal weights (3) and (3). Each of the pair of advance angle restrictors (48), (48) is engaged with each of the pair of advance angle restricting communication holes (45), (45), and each of the pair of advance angle restrictors (41) ) (41) and a pair of advance limiters (42) and (42) at the time of each engine operation are configured to be received by the one that is put into the advance limit position.

The input wheel (1) constituting the eccentric cam type mechanical timer of the engine is arranged on one lateral side of the pair of centrifugal weights (3) and (3), and the advance limit plate (44) is arranged on the other side. ). A pair of eccentric input pins (28), (28) for advancing the eccentric cam type advance mechanism (4) is penetrated laterally and fixed to the pair of centrifugal weights (3) (3). .
Of the pair of eccentric input pins (28), (28), the other ends (49), (49) of the eccentric input pins projecting outward from the other lateral sides of the centrifugal weights (3), (3) Each of the advance angle limiters (48) and (48) is configured.

  The advance angle limiting switching transmission device (43) includes at least a pair of driven holes (38) and (38) and a pair of main driving pins (39) and (39). The pair of driven holes (38) and (38) are formed in the advance limit plate (44). The pair of main driving pins (39), (39) are engaged with the pair of driven holes (38), (38) and interlocked with the starting advance angle releasing shape memory springs (8), (8).

  Based on the temperature sensitive expansion / contraction operation of the starting advance angle release shape memory springs (8) and (8), the advance angle is restricted from the pair of main drive pins (39) and (39) through the pair of driven holes (38) and (38). Through the transmission to the plate (44), one of the pair of cold start start advancement restricting bodies (41) (41) and the engine operation advancement restricting bodies (42) (42) is set to the advance advance restricting position. It is configured to receive the pair of advance angle limiters (48) and (48).

  The outer casing (10) of the transmission cylinder (9) (9) inserted between the starting advance angle release shape memory spring (8) (8) and the starting advance spring (6) (6). From (10), the main driving pins (39) and (39) are fixedly projected to the advance angle limiting plate (44) side and engaged with the driven holes (38) and (38).

  The advance angle device at the time of cold start of the eccentric cam type mechanical timer of the engine of the present invention is suitable, for example, as the advance angle device at the time of cold start of the eccentric cam type mechanical timer used in a diesel engine.

1 to 6 show Embodiment 1 of an advance device at the time of cold start of an eccentric cam type mechanical timer of an engine of the present invention. FIG. 1 shows a centrifugal weight of an eccentric cam type mechanical timer in which a weight returning spring, a spring for starting advancement, and a temperature sensitive operating spring are incorporated. 1A is a cross-sectional front view taken along line AA of FIG. 1B, FIG. 1B is a plan view, FIG. 1C is a left side view, and FIG. 1D is FIG. It is the DD sectional view taken on the line. 1E is a view taken in the direction of arrow E in FIG. 1B, showing a front view of the advance angle limiting device 40, and FIG. 1F is a sectional view taken along line FF in FIG. is there.

FIG. 2 is a vertical right side view of a drive unit for a fuel injection pump of a water-cooled vertical diesel engine. 3A is a vertical right side view of the eccentric cam type mechanical timer, FIG. 3B is a cross-sectional view taken along line BB of FIG. 3A, and FIG. 3C is C of FIG. FIG.

FIG. 4 is an enlarged view of a portion IV in FIG. FIG. 4A shows the contraction operation state of the shape memory spring for releasing the starting advance angle when the temperature is sensed on the low temperature side. FIG. 4B shows an extension operation state at the time of high-temperature temperature sensing of the shape memory spring for starting advance angle cancellation. FIG. 5 is a front view of the advance angle limiting device 40 and corresponds to FIG. FIG. 5A shows the advance angle limited state when the engine is cold start, and FIG. 5B shows the advance angle limited state during engine operation.

FIG. 6 is an advance operation characteristic curve diagram with respect to the engine rotation speed of both centrifugal weights. FIG. 6A is an advance operation characteristic curve diagram when the engine is cold-started, and shows the operation characteristic in the state of FIG. FIG. 6 (B) is an advance operation characteristic curve diagram during the operation of the engine, and shows the operation characteristic in the state of FIG. 5 (B).

FIG. 7 shows an advance device at the time of cold start of the eccentric cam type mechanical timer of the prior art engine. FIG. 7A is a longitudinal left side view of the eccentric cam type mechanical timer, and is a cross-sectional view taken along line AA in FIG. 7B. FIG. 7B is a longitudinal front view of the central portion of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Input wheel, 2 ... Output wheel, 3 * 3A * 3B ... Centrifugal weight, 4 ... Eccentric cam type advance mechanism, 5 ... Weight return spring, 6 ... Spring for starting advance, 7 ... Feeling for canceling start advance Temperature actuating means, 8 ... Shape memory spring for releasing the starting advance angle, 9 ... Transmission cylinder, 10 ... Outer rod, 11 ... Inner rod, 12 ... Spring base end, 13 ... Spring tip,

  DESCRIPTION OF SYMBOLS 14 ... Weight opening / closing guide shaft, 15 ... Spring base short part, 16 ... Spring tip part, 28 ... Eccentric input pin, 38 ... Drive hole, 39 ... Main drive pin, 40 ... Advance angle limiting device, 41 ... Advance angle at the time of cold start Limit body, 42 ... Advance limit body during engine operation, 43 ... Advance limit switch transmission, 44 ... Advance limit plate,

45 ... Advance limiting communication hole, 46 ... Advance limiting long hole for cold start, 47 ... Advance limiting long hole for engine operation, 48 ... Advance limiting body, 49 ... Other end of eccentric input pin, Lc: Advance limit position at cold start, Lw: Advance limit position at engine operation, Θ: Advance amount.

Claims (8)

An output wheel (2) is arranged on one side of the input wheel (1) constituting the eccentric cam type mechanical timer of the engine, and a pair of centrifugal weights (3) (3) are arranged on the other side,
An eccentric cam type advance mechanism (4) is provided over the input wheel (1) and the output wheel (2), and this eccentric cam type advance mechanism (4) is composed of a pair of centrifugal weights (3) (3). Actuated by the unbalanced force between the centrifugal force and the tension to the centripetal side of the weight return spring (5) made of compression coil spring, so that the output wheel (2) is controlled to advance the input wheel (1). To configure
The pair of centrifugal weights (3) and (3) are driven to advance in the centrifugal direction by a starting advance spring (6) made of a compression coil spring. It is configured to release the advance drive against the tension of the starting advance spring (6) by the extension operation when the temperature is sensed on the high temperature side.
When the engine is cold-started, the starting angle release temperature sensing means (7) is contracted by the low temperature side temperature sensing, and a pair of centrifugal weights (3) (3) is applied by the tension of the starting angle advance spring (6). Is configured to expand to the advance angle limit position (Lc) at the time of cold start,
When the engine is warm, the starting advance angle releasing temperature sensing means (7) is extended by the high temperature side temperature sensing to contract the starting advance angle spring (6), and this starting advance angle spring (6) Is configured to cancel the expansion of the pair of centrifugal weights (3) and (3) to the advance limit position (Lc) at the time of cold start.
In the advance device for cold start of the eccentric cam type mechanical timer of the engine,
The starting advance angle canceling temperature-sensitive operating means (7) is constituted by a starting advance angle canceling shape memory spring (8) made of a shape memory alloy material.
The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are positioned between the pair of centrifugal weights (3), (3), and the weight return spring ( 5) Concentrically with respect to
An advance angle limiting device (40) is attached to the pair of centrifugal weights (3), (3), and the advance angle limiting device (40) includes at least a pair of advance limiters (41) (41) at the time of cold start. A pair of advance limiters (42) and (42) during engine operation, and a transmission device (43) and (43) for advance angle limit switching,
The pair of cold start starting advancement restricting bodies (41) and (41) are used to determine the amount of advancement (Θ) that the pair of centrifugal weights (3) and (3) open in the centrifugal direction. It is configured to receive a pair of centrifugal weights (3) and (3) so as to forcibly limit to (Lc),
The pair of engine operation advance angle limiting bodies (42), (42) is configured to force a pair of centrifugal weights (Θ) to forcibly limit the advance amount (Θ) to the engine operation advance angle limiting position (Lw). 3) (3) Configure to receive each other,
The cold start start advance limit position (Lc) is set to a value larger than the engine operation advance advance limit position (Lw),
The pair of cold start start angle restricting bodies (41) and (41) and the pair of engine operation advance angle restricting bodies (42) and (42) are advanced relative to the pair of centrifugal weights (3) and (3). It is possible to selectively switch between an angle limit position and an advance angle limit release position, and this switching operation is canceled via the advance angle limit switching transmission device (43) (43). It is configured to be interlocked with the shape memory spring (8) (8),
The shape memory springs (8) and (8) for releasing the starting advance angle are in a state of being contracted by the low temperature side temperature sensing, while on the other hand, the pair of centrifugal weights (3 ) (3) is expanded to the cold start start advance limit position (Lc), and on the other hand, the advance limit restricting body during engine operation (43) (43) is provided via the advance limit changeover transmission (43) (43). 42) (42) is retracted to the advance limit release position, and the cold start start advance limit body (41) (41) is configured to enter the advance limit position,
On the other hand, the shape advance springs 8 and 8 for releasing the starting advance angle contract the starting advance springs 6 and 6 on the other hand in a state where the extension memory is operated by the high temperature side temperature sensing. The starting advance spring (6) (6) releases the pair of centrifugal weights (3) and (3) from being pushed and expanded to the cold start starting advance limit position (Lc). Via the limit switching transmission device (43) (43), the cold start starting advancement restricting body (41) (41) is retracted to the advance limit restricting position and the engine operating advancement restricting body (42 ) (42) is configured to enter the advance limit position,
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 1,
Of the pair of centrifugal weights (3) and (3), one of the centrifugal weights (3A) (3B) is provided with a weight return spring (5), whereas the other centrifugal weight (3B) ) (3A) is provided with a start advance spring (6) and a start advance release shape memory spring (8).
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 2,
The start-advance-releasing shape memory spring (8) and the start-advance spring (6) are configured to be inserted and inserted into each other.
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 3,
A transmission cylinder (9) is inserted between the starting advance angle release shape memory spring (8) and the starting advance angle spring (6), which are inserted and fitted to each other, and the transmission cylinder (9) The outer rod (10) is continuously extended from the one end of the tube to the centrifugal side, whereas the inner rod (11) is continuously extended from the other end of the tube to the centripetal side,
The other centrifugal weight (3B) (3A) of the pair of centrifugal weights (3), (3) is made to receive the spring base end (12) of the starting advance spring (6). The spring tip (13) of the starting advance spring (6) is configured to press the one centrifugal weight (3A) (3B) to the centrifugal side via the outer casing (10),
The other centrifugal weight (3B) (3A) receives the spring base end (15) of the starting advance angle release shape memory spring (8) via the weight opening / closing guide shaft (14), and this starting advance angle The spring tip (16) of the release shape memory spring (8) compresses the starting advance spring (6) through the inner rod (11), transmission cylinder (9), and outer rod (10) in this order. Configured to repress to the side
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 1, 2, 3 or 4,
An advance limit plate (44) is provided on the lateral side of the pair of centrifugal weights (3) and (3), and this advance limit plate (44) is a fulcrum about the rotational axis of the centrifugal weights (3) and (3). As a reciprocating pivot,
A pair of advance angle limiting communication holes (45) (45) is formed in the advance angle limiting plate (44), and the pair of advance angle limiting communication holes (45) (45) The long holes for limiting the advance angle (46) (46) and the pair of long holes for limiting the advance angle (47) (47) at the time of each engine operation are arranged side by side in the rotational direction of the centrifugal weights (3) (3). Made up of
The pair of cold start timing advancement restricting bodies (41) (41) are formed by the centrifugal side peripheral wall portions of the pair of cold start starting advance angle limiting slots (46, 46). Each engine operation advance angle limiting body (42) (42) is formed at each centrifugal side peripheral wall portion of each engine operation advance angle limiting elongated hole (47) (47),
A pair of advance angle restrictors (48), (48) are fixedly provided from the lateral sides of the pair of centrifugal weights (3), (3), and the pair of advance angle restrictors (48) ( 48) is engaged with each of the pair of advance angle limiting communication holes (45) (45), and each of the pair of cold start start angle limiting bodies (41) (41) and the pair of each engine operation advance angle. The limit body (42) (42) is configured to be received by the one inserted into the advance angle limit position,
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 5,
The input wheel (1) constituting the eccentric cam type mechanical timer of the engine is arranged on one lateral side of the pair of centrifugal weights (3) and (3), and the advance limit plate (44) is arranged on the other side. )
A pair of eccentric input pins (28), (28) for advancing the eccentric cam type advance mechanism (4) is fixed by penetrating the pair of centrifugal weights (3), (3) in the lateral direction. ,
Of the pair of eccentric input pins (28), (28), the other pair of eccentric input pins (49) (49) projecting outward from the other lateral sides of the centrifugal weights (3) (3). Configured each advance angle limiter (48) (48),
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 5 or 6,
The advance angle limit switching transmission device (43) comprises at least a pair of driven holes (38) (38) and a pair of main driving pins (39) (39),
The pair of driven holes (38) and (38) are formed in the advance limit plate (44), and the pair of main driving pins (39) and (39) are engaged with the pair of driven holes (38) and (38). And interlocked with the shape memory springs (8) and (8) for releasing the starting advance angle,
Based on the temperature sensitive expansion / contraction operation of the starting advance angle release shape memory springs (8) and (8), the advance angle is restricted from the pair of main drive pins (39) and (39) through the pair of driven holes (38) and (38). Through the transmission to the plate (44), one of the pair of cold start start advancement restricting bodies (41) (41) and the engine operation advancement restricting bodies (42) (42) is set to the advance advance restricting position. It was configured to receive the pair of advance angle limiters (48) (48) with the one that was thrown,
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine. An advance angle device at the time of cold start of an eccentric cam type mechanical timer for an engine according to claim 7 dependent on claim 4.
The outer casing (10) of the transmission cylinder (9) (9) inserted between the starting advance angle release shape memory spring (8) (8) and the starting advance spring (6) (6). From (10), the main driving pin (39) (39) is fixedly projected to the advance limit plate (44) side and engaged with the driven hole (38) (38).
An angle advance device at the time of cold start of an eccentric cam type mechanical timer for an engine.

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