JP4286756B2 - 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. 3D is a perspective view of the rotational advance limit device 35. 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, whereas the temperature sensing means (7) has a high temperature side temperature sensing. The advance drive is released against the tension of the starting advance spring (6) by the extension operation at that time.

  When the engine is cold-started, as shown in FIG. 4A, the temperature-sensing operation means (7) is contracted by the low-temperature side temperature sensing, and a pair of centrifugal weights are applied by the tension of the starting advance spring (6). (3) It is configured to expand (3) to the starting advance position.

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

[Conventional technology]
In the above premise configuration, as a configuration for combining the starting advance spring (6) and the temperature sensitive operation means (7), there is the conventional technology as 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 sensitive operating means (7) comprises a wax-sealed 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). The centrifugal cams (3) and (3) are configured to be expanded to the starting advance position by pressing the conical cam (52) against the conical hole cam surface (51) with the tension of the starting advance spring (6). Has been.

[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 temperature-sensitive operation means can be reduced in size and size. 3: The durability of the force transmission portion from the start advance angle spring to the centrifugal weight is improved.

[B]. By arranging the shape memory spring and the starting advance spring concentrically with respect to the weight return spring, the length of the centrifugal weight in the rotational axis direction is shortened.
[C]. During cold start of the engine, both the centrifugal weights are freely expanded in the centrifugal direction by a separation distance (Lc) for the cold start advance angle, and the start angle operation is sufficiently performed, so that the engine is reliably and powerfully started. When the engine is in operation, the advance operation between the two centrifugal weights is limited to the warm weight movement allowable distance (Lw), so that NOx and combustion noise generated when this advance angle is excessive are generated. Resolve problems such as increased volume.

[D]. 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 and shortening the length of the centrifugal weight.
[E]. The 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, thereby increasing the control accuracy of the starting advance angle during the cold start of the eccentric cam type mechanical timer.

[F]. In addition to increasing the control accuracy of the start angle at the time of cold start of the eccentric cam type mechanical timer, the durability of the start angle advance spring and the shape memory spring is increased.
[G]. The structure of the rotation advance limit device can be manufactured easily and inexpensively and has excellent durability.

  [Chi]. Allowing weight movement during warming as shown in FIG. 5 (B) by positioning the weight-locking member with respect to the outer casing and spring tip with high accuracy and stability without rattling in the opening and closing directions of both centrifugal weights. By ensuring the distance (Lw) with high accuracy, the advance angle limit value at the time of restarting the engine warm-up and during operation is maintained with high accuracy.

  [Li]. The weight-locking pin is allowed to move straight during the warming time shown in FIG. 5 (B) by guiding it straight from both sides with an oval member and accurately receiving it at the regular receiving position of the long circular free end portion. The distance (Lw) is ensured with high accuracy, and the advance angle limit value during engine operation is maintained with high accuracy.

  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. As a configuration for combining the spring (6) and the temperature sensitive operation means (7), the following characteristic configuration is added.

  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.

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. 3D is a perspective view of the rotational advance limit device 35. FIG.
FIG. 4 is an enlarged view of a portion IV in FIG. FIG. 4A shows a contraction operation state when the shape memory spring is sensed on the low temperature side. FIG. 4B shows an extension operation state at the time of temperature sensing of the shape memory spring.

  FIG. 5 shows the advance operation state of both centrifugal weights. FIG. 5A shows the advance operation state at the time of start-up in the cold state of the engine, and is the same diagram as FIG. FIG. 5 (B) shows the advance operation state during operation in the warm state of the engine.

  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 temperature sensitive operating means (7) is constituted by a shape memory spring (8) made of a shape memory alloy material for a compression coil spring. The shape memory spring (8) and the starting advance spring (6) are positioned between the pair of centrifugal weights (3) and (3), and with respect to the weight return spring (5). Place them concentrically.

  A rotation advance limit device (35) is provided across the starting advance spring (6) and one of the centrifugal weights (3A) (3B). The rotation advance limit device (35) is configured to limit the maximum distance between the pair of centrifugal weights (3A) and (3B) during warming as the warming weight movement allowable distance (Lw). It is characterized by that.

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 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 shape memory spring (8) and the starting advance spring (6) are arranged 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 shape memory spring (8) and the start-advance spring (6) which are fitted in and out of 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 shape memory spring (8) via the weight opening / closing guide shaft (14), and the spring of the shape memory spring (8). The tip (16) is configured to repress the starting advance spring (6) toward the side to be compressed through the inner rod (11), the transmission cylinder (9), and the outer rod (10) in this order. It is characterized by that.

The invention of claim 5. See FIGS.
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.

  The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). . The weight locking member (37) is fixed to the spring interlocking member (36). The weight locking member (38) is fixed to the one centrifugal weight (3A) (3B).

The invention of claim 6. See FIGS.
The invention of claim 6 is characterized in that, in the invention of claim 4, the following characteristic configuration is added.

  The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). . The weight locking member (37) is fixed to the spring interlocking member (36). The weight locking member (38) is fixed to the one centrifugal weight (3A) (3B).

  The spring interlocking member (36) is formed in a ring shape. The ring-shaped spring interlocking member (36) is externally fitted to the interlocking cylinder (9), and the outer flange (10) of the transmission cylinder (9) and the starting advance spring (6 ) Between the spring tip (13). The spring tip (13) is configured to serve as a spring expansion / contraction moving part (6a).

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

  The weight locking member (37) includes an oblong free end portion (37a) of an oval member (39). The weight locked member (38) is composed of a weight locked pin (38a). The weight locking pin (38a) is fixedly provided so as to protrude from the one centrifugal weight (3A) (3B) in a direction crossing the centrifugal movement direction. The weight locking pin (38a) is slidably fitted in the oval member (39), and is characterized in that

  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 starting advance spring (6) and the shape memory spring (8) can be reduced in capacity and size. Effect 3: From the starting advance spring (6) to the centrifugal weight ( 3) The durability of the force transmission part up to (3) is improved. ]

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

  From this characteristic configuration, when the engine is cold-started, as illustrated in FIG. 4A, the shape memory spring (8) is contracted, and a pair of centrifugal weights ( 3) Push (3) to the starting advance angle position, and as shown in FIGS. 1 and 3, the fuel injection timing of the fuel injection pump (19) is set to advance for cold start via the advance mechanism (4). Advance to the angular position.

  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 spring (6) and the 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 memory spring (8) and the start-advance spring (6) need not be displaced in the rotational axis direction of the centrifugal weights (3) and (3) with respect to the weight return spring (5). The length of the centrifugal weights (3) and (3) is shortened, which contributes to shortening the total length of the eccentric cam type mechanical timer. ]

  As illustrated in FIGS. 1 and 4, the shape memory spring (8) and the starting advance spring (6) are positioned between the centrifugal weights (3) and (3) with respect to the weight return spring (5). The length of the centrifugal weights (3) and (3) in the direction of the rotational axis is shortened by the amount that the centrifugal weights (3) and (3) need not be displaced in the direction of the rotational axis. Thus, the overall length of the eccentric cam type mechanical timer can be reduced.

[Effect C. Effect 4: Both the centrifugal weights (3A) and (3B) are sufficiently expanded in the centrifugal direction by a distance for the cold start advance angle (Lc) required at the time of cold start of the engine. So, make sure the engine is cold and start
Effect 5: When the engine is in operation, the advance operation between the centrifugal weights (3A) and (3B) is limited to the warm weight movement allowable distance (Lw). Thus, it is possible to achieve both the elimination of 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.
One centrifugal weight (3A) (3B) of the pair of centrifugal weights (3), (3) is elastically pressed toward the centripetal side by the tension of the weight return spring (5), whereas the starting advance spring It is configured to move to the centrifugal side against the tension of the weight return spring (5) with the tension of (6).

  A rotation advance limit device (35) is provided across the starting advance spring (6) and one of the centrifugal weights (3A) (3B). The rotation advance limit device (35) is configured to limit the maximum distance between the pair of centrifugal weights (3A) and (3B) as the warm weight movement allowable distance (Lw).

From this characteristic configuration, the following effects 4 and 5 are produced.
Effect 4: Both the centrifugal weights (3A) and (3B) are sufficiently expanded in the centrifugal direction by the distance for the cold start advance angle (Lc) required when starting the engine cold, and the start advance operation is sufficiently performed. Therefore, make sure that the engine is cold-started reliably and powerfully.

  At the time of cold start when the engine is not yet warmed, as shown in FIGS. 5A and 6A, the shape memory spring (8) contracts due to the low temperature side temperature sensing operation, and the starting advance spring (6) However, both centrifugal weights (3A) and (3B) are pushed and expanded in the centrifugal direction by a distance (Lc) for the cold start angle.

  At this time, the rotational advance limit device (35) operates toward the rotational advance restriction release side as the starting advance spring (6) extends, and the one centrifugal weight (3A) (3B) side Therefore, there is no limitation on the distance that the centrifugal weights (3A) and (3B) are separated in the centrifugal direction.

  As a result, both the centrifugal weights (3A) and (3B) are freely expanded largely in the centrifugal direction by the distance for the cold start angle (Lc) required at the time of cold start of the engine. Therefore, start the engine coldly and reliably.

  Effect 5: When the engine is in operation, the advance operation between the centrifugal weights (3A) and (3B) is limited to the allowable weight movement distance (Lw) during warm-up, eliminating excessive advance during high-speed rotation. This eliminates problems such as an increase in the amount of NOx and combustion noise generated when the advance angle is excessive.

  When the warmer is restarted and the engine is running, as shown in FIGS. 5 (B) and 6 (B), the shape memory spring (8) is extended by the high temperature side temperature sensing operation, and the start-up progress is made. Since the angular spring (6) is contracted and the rotational advance limit device (35) is moved to the rotational advance limit side, the distance that the centrifugal weights (3A) (3B) are opened in the centrifugal direction is set to It is limited to the weight movement allowable distance (Lw) during warming.

  Therefore, at the time of restarting the engine warm-up and during operation, the advance operation between the centrifugal weights (3A) (3B) is less than the cold-start start advance distance (Lc). Since it is limited to the allowable movement distance (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. .

As described above, the effect 4: Both the centrifugal weights (3A) and (3B) are sufficiently expanded and expanded in the centrifugal direction by the separation distance (Lc) required for starting the cold start of the engine. Since the start angle is operated, the engine is surely and powerfully started cold,
Effect 5: When the engine is in operation, the advance operation between the centrifugal weights (3A) and (3B) is limited to the allowable weight movement distance (Lw) during warm-up, eliminating excessive advance during high-speed rotation. Thus, it is possible to achieve both the elimination of problems such as an increase in the amount of NOx and combustion noise generated when the advance angle is excessive.

O Invention of claim 2. See FIG. 1 and FIG.
The invention of claim 2 has the following effects in addition to the effects [Effects], [Effects B] and [Effects C] of the invention of Claim 1 above.

  [Effects d. The length of the centrifugal weights (3) and (3) is further shortened by the amount that can reduce the maximum outer diameter of the weight return spring (5), starting advance spring (6), and shape memory spring (8). 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 shape memory spring (8).

  Because of this characteristic configuration, the weight return spring (5), the starting advance spring (6), and the shape memory spring (8) need only be inserted into and out of the three springs (5). (6) The length of the centrifugal weights (3) and (3) can be shortened by the amount that the maximum spring outer diameter of (8) can be reduced, thereby contributing to the shortening of the total length of the eccentric cam type mechanical timer. .

The invention of claim 3. See FIG. 1 and FIG.
In addition to [Effect A], [Effect B], [Effect C] of the invention of Claim 1 and [Effect D] of the invention of Claim 2, the invention of Claim 3 has the following effects.

  [Effect E. The shape memory spring (8) and the starting advance spring (6) reduce 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, thereby cooling the eccentric cam type mechanical timer. Increase the control accuracy of the lead angle at the start. ]

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

  Because of this characteristic configuration, the shape memory spring (8) and the starting advance spring (6) are inserted into each other and inserted into each other, so that the springs (8) and (6) of each spring (8) and (6) are compared with each other. As the spring length can be increased, the rate of change of spring tension with respect to the amount of spring expansion and contraction can be reduced, and the advance angle control accuracy at the time of cold start of the eccentric cam type mechanical timer can be increased.

The invention of claim 4. See FIG. 1 and FIG.
The invention of claim 4 is the [Effect A], [Effect B], [Effect C] of the invention of Claim 1 above, [Effect D] of the invention of Claim 2, and [Effect of the invention of Claim 3]. In addition to E], the following effects are achieved.

  [Effects. The starting advance spring (6) and the 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 shape memory spring (8) and the start-advance spring (6) which are fitted in and out of 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 shape memory spring (8) via the weight opening / closing guide shaft (14), and the spring of the shape memory spring (8). The tip (16) is configured to repress the start advance spring (6) toward the side to be compressed through the inner rod (11), the transmission cylinder (9), and the outer rod (10) in this order.

  Due to this characteristic configuration, the starting advance spring (6) and the shape memory spring (8) are accurately and stably passed through the outer casing (10), the transmission cylinder (9) and the inner casing (11) in this order. Can be balanced and operated. 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 FIGS.
In addition to the [Effect A] / [Effect B] and [Effect C] of the first aspect of the invention, the invention of claim 5 has the following effects.

  [Effects. The rotation advance limit device (35) is composed of only three components: a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). And the weight locking member (37) are linked to the starting advance spring (6), and the weight locked member (38) is fixed to the one centrifugal weight (3A) (3B). The configuration of the rotation advance limit device (35) is simple and can be manufactured at low cost and has excellent durability.]

The invention of claim 5 has the following characteristic configuration.
The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). . The weight locking member (37) is fixed to the spring interlocking member (36). The weight locking member (38) was fixed to the one centrifugal weight (3A) (3B).

  From this characteristic configuration, the rotation advance limit device (35) is composed of only three components: a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). The interlocking member (36) and the weight locking member (37) are interlocked with the starting advance spring (6), and the weight locked member (38) is the one centrifugal weight (3A) ( Since it is only necessary to fix to 3B), the configuration of the rotation advance limit device (35) is simple and inexpensive to manufacture, and also has excellent durability.

The invention of claim 6. See FIGS.
The invention of claim 6 is the [Effect A], [Effect B], [Effect C] of the invention of Claim 1 above, [Effect F] of the invention of Claim 4, and [Effect of the invention of Claim 5] In addition to the above, the following effects are achieved.

  [Effect H. The weight locking member (37) is positioned with high precision and stability without rattling in the opening / closing direction of the centrifugal weights (3A) (3B) with respect to the outer cage (10) and the spring tip (13). 5 (B) ensures that the warming weight movement allowable distance (Lw) shown in FIG. 5 (B) is ensured with high accuracy, so that the advance angle limit value is maintained with high accuracy when the engine is warming up and running. can do. ]

The invention of claim 6 has the following characteristic configuration.
The spring interlocking member (36) is formed in a ring shape. The ring-shaped spring interlocking member (36) is externally fitted to the interlocking cylinder (9), and the outer flange (10) of the transmission cylinder (9) and the starting advance spring (6 ) Between the spring tip (13). The spring tip (13) is configured to also serve as a spring expansion / contraction movement part (6a).

  Due to this characteristic configuration, the ring-shaped spring interlocking member (36) is externally fitted to the transmission cylinder (9) and is positioned stably in the radial direction, and the outer casing (10) and the starting advance angle It is clamped between the outer spring (10) and the spring tip (13) by being clamped between the spring tip (13) of the spring (6) and firmly fixed in the axial direction. The locking member (37) is positioned with high accuracy and stability without rattling in the opening / closing direction of the centrifugal weights (3A) (3B).

  As a result, the warm-up time weight movement allowable distance (Lw) shown in FIG. 5B is secured with high accuracy, so that the advance angle limit value at the time of engine warm-up restart and during operation is highly accurate. Can be held.

The invention of claim 7. See FIGS.
The invention of claim 7 is the [Effect A], [Effect B], [Effect C] of the invention of Claim 1, the [Effect F] of the invention of Claim 4, and the [Effect G] of the invention of Claim 5. In addition to [Effect H] of the invention of claim 6, the following effects are obtained.

  [Effects. The weight locking pin (38a) is guided in a straight line from both sides by the oval member (39) and accurately received at the regular receiving position of the oval free end portion (37a). The warming time weight movement allowable distance (Lw) shown in FIG. 4 is ensured with high accuracy, so that the advance angle limit value during engine operation can be maintained with high accuracy. ]

The invention of claim 7 has the following characteristic configuration.
The weight locking member (37) includes an oblong free end portion (37a) of an oval member (39). The weight locked member (38) is composed of a weight locked pin (38a). The weight locking pin (38a) is fixedly projected from the one centrifugal weight (3A) (3B) in a direction crossing the centrifugal movement direction. The weight locking pin (38a) was slidably fitted into the oval member (39).

  From this characteristic configuration, the weight locking pin (38a) is guided straight from both sides by an oval member (39), and is accurately received at the regular receiving position of the oval free end portion (37a), There is no positional deviation from the normal receiving position.

  As a result, the warm-up time weight movement allowable distance (Lw) shown in FIG. 5B is secured with high accuracy, so that the advance angle limit value at the time of engine warm-up restart and during operation is highly accurate. Can be held.

  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.

  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. 3D is a perspective view of the rotational advance limit device 35. FIG.

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

  FIG. 5 shows the advance operation state of both centrifugal weights. FIG. 5A shows the advance operation state at the time of start-up in the cold state of the engine, and is the same diagram as FIG. FIG. 5 (B) shows the advance operation state during operation in the warm state of the engine.

  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, whereas the temperature sensing means (7) has a high temperature side temperature sensing. The advance drive is released against the tension of the starting advance spring (6) by the extension operation at that time.

  At the time of engine cold start, as shown in FIG. 4 (A), the temperature sensing means (7) is contracted by the low temperature side temperature sensing, and a pair of centrifugal weights ( 3) (3) is configured to expand to the starting advance position.

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

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 ring eccentrics (27) are fitted in each small ring pivot support hole (26) and pivotally supported rotatably.

  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 FIGS. 1 and 4, the temperature-sensing operation means (7) is composed of a shape memory spring (8) made of a shape memory alloy material and a compression coil spring. The shape memory spring (8) and the starting advance spring (6) are positioned between the pair of centrifugal weights (3) and (3), and with respect to the weight return spring (5). Place them concentrically.

  As shown in FIGS. 3 to 5, a rotation advance limit device (35) is provided across the starting advance spring (6) and one of the centrifugal weights (3A) (3B). The rotation advance limit device (35) is configured to limit the maximum distance between the pair of centrifugal weights (3A) and (3B) as the warm weight movement allowable distance (Lw).

  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 shape memory spring (8). The shape memory spring (8) and the starting advance spring (6) are inserted in and out of each other.

  A transmission cylinder (9) is inserted between the shape memory spring (8) and the start-advance spring (6) which are fitted in and out of 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 shape memory spring (8) via the weight opening / closing guide shaft (14), and the spring of the shape memory spring (8). The tip (16) is configured to repress the start advance spring (6) toward the side to be compressed through the inner rod (11), the transmission cylinder (9), and the outer rod (10) in this order.

  The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38). The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). . The weight locking member (37) is integrally fixed to the spring interlocking member (36). The weight locking member (38) is fixed to the one centrifugal weight (3A) (3B).

  The spring interlocking member (36) is formed in a ring shape. The ring-shaped spring interlocking member (36) is externally fitted to the interlocking cylinder (9), and the outer flange (10) of the transmission cylinder (9) and the starting advance spring (6 ) Between the spring tip (13). The spring tip (13) is configured to also serve as a spring expansion / contraction movement part (6a).

  The weight locking member (37) includes an oblong free end portion (37a) of an oval member (39). The weight locked member (38) is composed of a weight locked pin (38a). The weight locking pin (38a) is fixedly projected from the one centrifugal weight (3A) (3B) in a direction crossing the centrifugal movement direction. The weight locking pin (38a) is slidably fitted into the oval member (39).

  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.

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. 3D is a perspective view of the rotational advance limit device 35. FIG.

FIG. 4 is an enlarged view of a portion IV in FIG. FIG. 4A shows a contraction operation state when the shape memory spring is sensed on the low temperature side. FIG. 4B shows an extension operation state at the time of temperature sensing of the shape memory spring. FIG. 5 shows the advance operation state of both centrifugal weights. FIG. 5 (A) shows the advance operation state at the time of start-up in the cold state of the engine, and is the same view as FIG. 4 (A). FIG. 5 (B) shows the advance operation state during operation in the warm-up state of the engine.

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 ... Start advance spring, 6a ... Spring expansion-contraction movement part, 7 DESCRIPTION OF SYMBOLS ... Temperature-sensitive operation means, 8 ... Shape memory spring, 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 front-end | tip part, 35 ... Rotational advance angle limiting device, 36 ... Spring interlocking member, 37 ... Weight locking member, 37a ... Long circular free end part, 38 ... weight locked member, 38a ... weight locked pin, 39 ... oval member, Lc ... distance for cold start start angle, Lw ... weight movement allowable distance during warming.

Claims (7)

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, whereas the temperature sensing means (7) has a high temperature side temperature sensing. It is configured to release the advance drive against the tension of the starting advance spring (6) by the extension operation at the time,
At the time of engine cold start, the temperature sensing means (7) is contracted by the low temperature side temperature sensing, and the pair of centrifugal weights (3) (3) are moved to the starting advance position by the tension of the start advance spring (6). Configured to spread
When the engine is warm, the temperature-sensing operation means (7) is extended by the high-temperature side temperature sensing to contract the starting advance spring (6), and this starting advance spring (6) is a pair of centrifugal weights. (3) Configured to release the expansion of (3) to the starting advance position,
In the advance device for cold start of the eccentric cam type mechanical timer of the engine,
The temperature-sensitive operating means (7) is constituted by a shape memory spring (8) made of a shape memory alloy material for a compression coil spring,
The shape memory spring (8) and the starting advance spring (6) are positioned between the pair of centrifugal weights (3) and (3), and with respect to the weight return spring (5). Placed concentrically,
A rotation advance limit device (35) is provided between the starting advance spring (6) and one of the centrifugal weights (3A) (3B), and this rotation advance limit device (35) is a pair of centrifugal weights ( 3A) (3B) was configured to limit the maximum separation distance during warming as the warming weight movement allowable distance (Lw).
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 starting advance spring (6) and a 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 shape memory spring (8) and the starting 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 shape memory spring (8) and the start-advance spring (6) that are inserted and fitted to each other, and is removed from one end of the transmission cylinder (9). Whereas the rod (10) continues to the centrifugal side, the inner rod (11) continues 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). 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 shape memory spring (8) via the weight opening / closing guide shaft (14), and the spring of the shape memory spring (8). The tip (16) is configured to repress the starting advance spring (6) toward the side to be compressed through the inner rod (11), the transmission cylinder (9), and the outer rod (10) in this order.
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,
The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38),
The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). ,
The weight locking member (37) is fixed to the spring interlocking member (36), and the weight locked member (38) is fixed to the one centrifugal weight (3A) (3B),
An advance angle device at the time of cold start of an eccentric cam type mechanical timer of an engine characterized by being configured. In the advance device at the time of cold start of the eccentric cam type mechanical timer of the engine according to claim 4,
The rotation advance limit device (35) includes a spring interlocking member (36), a weight locking member (37), and a weight locked member (38),
The spring interlocking member (36) is interlocked and connected to a spring expansion / contraction moving part (6a) of the starting advance spring (6) that expands and contracts with respect to the other centrifugal weight (3B) (3A). ,
The weight locking member (37) is fixed to the spring interlocking member (36), and the weight locked member (38) is fixed to the one centrifugal weight (3A) (3B),
The spring interlocking member (36) is formed in a ring shape, and the ring-shaped spring interlocking member (36) is externally fitted to the interlocking cylinder (9), and the transmission cylinder (9) The outer flange (10) is clamped between the starting advance spring (6) and the spring tip (13), and the spring tip (13) is also used as a spring expansion and contraction moving part (6a). ,
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 weight locking member (37) comprises an oblong free end portion (37a) of an oval member (39),
The weight-locking member (38) is composed of a weight-locking pin (38a), and the weight-locking pin (38a) intersects the centrifugal movement direction from the one centrifugal weight (3A) (3B). Protruding and sticking in the direction,
The weight locking pin (38a) is slidably fitted into the oval member (39),
An advance angle device at the time of cold start of an eccentric cam type mechanical timer of an engine characterized by being configured.

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