JP2554877B2 - Control device for hydraulically actuated transmission for vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to at least a low speed transmission system and a high speed transmission system.
The present invention relates to a control device for a hydraulically actuated transmission for a vehicle, which is provided with a transmission system of stages and in which a one-way clutch that allows over-rotation on the output side is interposed in the low-speed transmission system.

(Prior Art) Conventionally, in this type of transmission, as seen in JP-A-59-166750, a low speed hydraulic engagement element that establishes a low speed transmission system and a high speed hydraulic engagement element that establishes a high speed electric system. The hydraulic circuit for controlling the oil supply and discharge to and from the coupling element is provided with a manual valve that can be switched between at least two positions of a neutral position and a traveling position, and a shift valve that can be switched between a low speed position and a high speed position. By switching the manual valve to the traveling position, the low-speed hydraulic engagement element and the high-speed hydraulic engagement element at its high-speed position via the shift valve are supplied with pressure oil from a hydraulic source,
When switching the manual valve from the neutral position to the running position and starting, first refuel only the low speed hydraulic engagement element to establish a low speed transmission system, and then switch the shift valve to the high speed position to switch to the high speed hydraulic engagement element. It refuels and establishes a high-speed transmission system.

Here, according to the oil supply to the high-speed hydraulic engagement element, the torque transmission via the low-speed transmission system is automatically stopped by the action of the one-way clutch that intervenes in the low-speed transmission system even if the low-speed hydraulic engagement element is supplied with oil. The high speed transmission system is established.

(Problems to be Solved by the Invention) In the above, when the vehicle is started by switching the manual valve to the traveling position, the drive that acts on the drive wheels of the vehicle by the transmission of a relatively high torque via the low speed transmission system. There is a problem that the rise of torque becomes steep and a shock is likely to occur.

SUMMARY OF THE INVENTION In view of the above points, an object of the present invention is to provide a device capable of gradually raising the drive torque and reducing the switching shock when switching the manual valve to the traveling position.

(Means for Solving the Problems) In order to achieve the above object, the present invention is provided with at least two stages of a low speed transmission system and a high speed transmission system, and the low speed transmission system is provided with over-rotation on the output side. A control device for a hydraulically actuated transmission for a vehicle, which includes an allowable one-way clutch, comprising: a low speed hydraulic engagement element for establishing the low speed transmission system and a high speed hydraulic engagement element for establishing the high speed transmission system. The hydraulic circuit for controlling the oil supply / drainage is provided with a manual valve that can be switched to at least two positions of a neutral position and a running position 4, and a shift valve that can be switched to at least two positions of a low speed position and a high speed position, Pressure oil from a hydraulic source is supplied to the low speed hydraulic engagement element by switching the manual valve to the traveling position and further to the high speed hydraulic engagement element at the high speed position via the shift valve. At the manual valve and An oil passage for connecting the high-speed hydraulic engagement element to the hydraulic power source is provided when the shift valve and the low-speed position are in the traveling position and the oil passage, and an open position for communicating the oil passage and the oil passage are connected to the oil passage. A control valve that can be switched to a closed position where communication is cut off and oil is drained from the high-speed hydraulic engagement element is interposed, and the control valve is closed when the hydraulic pressure of the low-speed hydraulic engagement element rises to a predetermined pressure. The switch is switched to a position, and further, an orifice is provided in an oil passage connecting the low speed hydraulic engagement element to the hydraulic power source at the traveling position of the manual valve, and
The orifice communicating with the closed position of the control valve is provided with a parallel side passage.

(Operation) When the manual valve is switched from the neutral position to the running position and the vehicle starts when the shift valve is in the low speed position, the control valve is initially in the open position. Is also refueled, and the torque transmission via the low speed transmission system is stopped by the intervening movement of the one-way clutch, so that a relatively low torque is first transmitted to the drive wheels of the vehicle via the high speed transmission system, and then the low speed transmission is performed. When the hydraulic pressure of the hydraulic engagement element rises to a predetermined pressure and the control valve is switched to the closed position, oil is drained from the high speed hydraulic engagement element, and torque transmission via the low speed transmission system is started. The drive torque acting on the drive wheels gradually rises gradually, and the switching shock is reduced.

By the way, if the hydraulic pressure of the low-speed hydraulic engaging element rises before the hydraulic pressure of the high-speed hydraulic engaging element rises, it becomes impossible to raise the drive torque stepwise, so that the low-speed hydraulic engaging element is supplied with oil through the orifice. As a result, the increase in the hydraulic pressure of the low speed hydraulic engagement element is delayed, but if the oil is supplied through the orifice even after the control valve is switched to the closed position, the engagement delay of the low speed hydraulic engagement element may occur. Startability is poor.

However, in the present invention, when the control valve is switched to the closed position, the low speed hydraulic engagement element is refueled via the side passage parallel to the orifice, so that the hydraulic pressure of the low speed hydraulic engagement element rapidly rises and the low speed hydraulic engagement element is increased. It is possible to prevent the startability from being deteriorated due to the delay of the engagement element.

The oil passage provided with the control valve is connected to the high-speed hydraulic engagement element when the shift valve is in the low speed position.
When the shift valve is switched to the high speed position after starting, drainage of oil from the high speed hydraulic engagement element via the control valve is stopped, oil is supplied to the engagement element, and a high speed transmission system is established.

(Example) The present invention will be described with reference to the illustrated example.

In FIG. 1, (1) shows a transmission that shifts three forward speeds and one reverse speed. The transmission (1) is connected to an engine (2) via a torque converter (3). 1a)
And the output shaft (1b) connected to the drive wheels (4) of the vehicle through the differential gear (5), the first to third forward transmission systems (G1) (G2) (G3) And a reverse transmission system (GR), and hydraulic clutches (C1) (C2) (C1) of the first to third speeds, which are hydraulic engagement elements, for the respective transmission systems (G1) (G2) (G3) for forward movement.
3) was intervened.

The reverse transmission system (GR) shares the second speed transmission system (G2) and the second speed hydraulic clutch (C2), and both transmission systems (G2) (GR) are selectors on the output shaft (1b). It is adapted to be selectively established through the gear (6).

In the drawing, (7) is a one-way clutch intervening in the first speed transmission system (G1), which operates to allow over-rotation on the output shaft (1b) side.

The hydraulic clutches (C1) (C2) (C3) are, for example, second
The oil supply / exhaust oil is controlled by the hydraulic circuit shown in the figure. The hydraulic circuit will be described in detail.
And a manual that can be switched between 5 positions: "P" for parking, "R" for reverse, "N" for neutral position, "D" for automatic gear shifting for running position, and "2" for holding second speed. Valve (9)
A shift valve (10) which is switched according to the vehicle speed and the throttle opening, and a servo valve (11) for switching between forward and backward movement which connects the selector gear (6) to each other. ) "D" position, the first oil passage (L1) connected to the hydraulic pressure source (8) is connected to the second oil passage (L2) connected to the shift valve (10), and via the shift valve (10). Oil supply and discharge to the hydraulic clutches (C2) and (C3) for the 2nd and 3rd speeds are performed.

Incidentally, the first speed hydraulic clutch (C1) is always supplied with oil via the third oil path (L3) branched from the second oil path (L2), and when shifting from the first speed to the second speed described later, The engagement force is gradually strengthened as the second speed hydraulic clutch (C2) is refueled, and the torque is transmitted through the second speed transmission system (G2) so that the rotation speed of the output shaft (1b) is the first speed transmission system (G1). When the speed is exceeded by the one-way clutch (7) described above
The torque transmission via the high speed transmission system (G1) is automatically stopped.

The shift valve (10) includes a first shift valve (10 ₁ ) for upstream first speed-second speed shift connected to each other through an intermediate fourth oil passage (L4), and a second speed downstream side. -3 speed shift second shift valve (10 ₂ ), each of the valves (10 ₁ ) (10 ₂ ) has a governor pressure corresponding to the vehicle speed from the governor valve (12) at one end, that is, the right end, and the left side. the first throttle valve (13 ₁₎ to the action of the throttle pressure according to the throttle opening from, first, the first shift valve by governor pressure according to the increase of the vehicle speed (10 ₁₎ of the first speed position of the right side ( (Position shown in the drawing) to the second speed position on the left side, and the second oil passage (L2) passes through the fourth oil passage (L4) to the fifth oil passage (outlet side of the second shift valve (10 ₂ ). L5),
The second speed hydraulic clutch (C) is connected through the sixth oil passage (L6) connected to the fifth oil passage (L5) at the "D" position of the manual valve (9).
2) is supplied with pressure oil from the hydraulic source (8),
When the vehicle speed is increased to a higher speed and the vehicle speed further increases, the second shift valve (10 ₂ ) moves from the second speed position on the right side (position shown in the figure) to the third speed position on the left side, and the fourth oil passage (L4) The fifth oil passage (L5) is switched and connected to the seventh oil passage (L7) connected to the third speed hydraulic clutch (C3), and the fifth oil passage (L5) is connected to the first oil discharge passage (LD1). Oil is discharged from the second speed hydraulic clutch (C2) and oil is supplied to the third speed hydraulic clutch (C3).
It has been made possible to shift up from second gear to third gear.

Further, due to deceleration, the second shift valve (10 ₂ ) is returned to the second speed position on the right side, and the fourth oil passage (L4) is moved to the fifth oil passage (L5) and the seventh oil passage (L5) as described above. L7) is switched and connected to the second oil discharge passage (LD2) to discharge oil from the third speed hydraulic clutch (C3) and supply oil to the second speed hydraulic clutch (C2). Downshifted to the first shift valve (10 ₁ )
Returns to the first speed position on the right side, and the fourth oil passage (L4) is connected to the oil discharge port (18a) of the control valve (18) described later, and oil is discharged from the second speed hydraulic clutch (C2). Then, the second gear is downshifted to the first gear.

In the drawing, (14) is a regulator valve for adjusting the hydraulic pressure supplied from the hydraulic pressure source (8) to a constant line pressure, (15 ₁ ) (15 ₂ ) (15
₃ ) indicates an accumulator connected to each of the hydraulic clutches (C1) (C2) (C3), and each hydraulic clutch (C1)
Orifices (16 ₁ ) (16 ₂ ) (16 ₃ ) and the accumulators (15 ₁ ) (15 ₂ ) (15) intervening in the oil passages (L3) (L5) (L7) connected to (C2) (C3) ₃ ) and each hydraulic clutch (C
1) In order to buffer the sudden pressure rise during refueling of (C2) and (C3), and to facilitate the shift of 2nd speed and 3rd speed, which is more likely to cause shift shock, each of 2nd speed and 3rd speed The accumulators (15 ₂ ) (15 ₃ ) are caused to act as a back pressure by the throttle pressure corresponding to the throttle opening from the second throttle valve (13 ₂ ) so that the accumulators (15 ₂ ) (15 ₃ ) have a cushioning effect. The pressure range to be generated is increased / decreased according to the throttle opening, and one-way valves (17 ₁ ) (17 ₂ ) are provided in parallel with each orifice (16 ₁ ) (16 ₂ ) to provide each hydraulic clutch (C1).
The oil was drained from (C2) quickly so that it could be obtained.

In the drawing, (L8) indicates an eighth oil passage connected to the fourth oil passage (L4) at the first speed position of the second shift valve (10 ₁ ), and
When the upstream end of the oil passage (L8) is connected to the second oil passage (L2) and the manual valve (9) and the first shift valve (10 ₁ ) are in the “D” position and the first speed position, respectively. The second speed hydraulic clutch (C2) is the hydraulic pressure source (8) on the route through the eighth oil passage (L8).
And disconnecting the communication between the eighth oil passage (L8) and the left open position (the position shown in the figure) that communicates the eighth oil passage (L8) with the eighth oil passage (L8). A control valve (18) that can be switched between the downstream side of the control valve (18a) and the closed position on the right side that connects to the oil discharge port (18a) is provided. The hydraulic pressure of the first speed hydraulic clutch (C1) is input through the pilot oil passage (L3a) branched from the passage (L3), and the control valve (18) causes the spring (18b) to rise when the hydraulic pressure rises to a predetermined pressure Ps. It was made possible to switch to the closed position against.

Further, it branched from the downstream-side portion of the orifice (16 ₁₎ to intervene the pilot oil path (L3a) in a third oil passage (L3), the oil passage (L3a) and the eighth oil passage (L8) in the upstream portion constitutes a bypass in parallel with the orifice (16 _1), said side passage in the closed position of the control valve (18) is to be communicated.

Next, to explain the operation of the above-described embodiment, when the manual valve (9) is switched from the "N" position to the "D" position to start, the pressure oil from the hydraulic pressure source (8) is transferred to the first oil passage ( L1) → second oil passage (L2) → third oil passage (L3) route is supplied to the first speed hydraulic clutch (C1), and the second oil passage (L2) to the eighth oil passage
The oil passage (L8) → the fourth oil passage (L4) → the fifth oil passage (L5) → the sixth oil passage (L6) is also supplied to the second speed hydraulic clutch (C2), and the second speed hydraulic clutch (C2) ) (Hereinafter referred to as second speed pressure) and the first speed hydraulic clutch (C1) hydraulic pressure (hereinafter referred to as first speed pressure) both increase as shown in FIG.

In this case, due to the action of the one-way clutch (7) intervening in the first speed transmission system (G1), torque transmission via the second speed transmission system (G2) takes precedence over the first speed transmission system (G1), and the drive wheels ( When a relatively low torque is transmitted to 4) via the second speed transmission system (G2), then the first speed pressure rises to a predetermined pressure Ps and the control valve (18) switches from the open position to the closed position, The control valve (1
The oil of the second speed hydraulic clutch (C2) is discharged from the oil discharge port (18a) of 8), the second speed pressure is reduced, and the torque transmission via the first speed transmission system (G1) is started. Thus, drive wheels (4)
The driving torque that acts on the torque gradually increases to a relatively low value due to the 2nd speed transmission system (G2) and a relatively high value due to the 1st speed transmission system (G1), and the rise of the torque becomes gentle, so that The shock that occurs when the valve (9) is switched to the "D" position is reduced.

Here, when the control valve (18) is switched to the closed position, via a parallel bypass of the orifice (16 ₁₎ 1-speed hydraulic clutch (C
As a result, the first speed pressure is rapidly increased, and deterioration of the starting performance due to the engagement delay of the first speed hydraulic clutch (C1) is prevented. After starting, the control valve (18) is held in the closed position, and the first shift valve (10 ₁ ) and the second shift valve (10 ₂ )
By changing over between 1 and 3, the first to third speeds are changed.

In the above embodiment, the second speed hydraulic clutch (C
2), but the downstream end of the eighth oil passage (L8) is connected to the second oil discharge passage (LD2) as shown by the phantom line in FIG. 2, and the third speed hydraulic clutch (C3 ) May be refueled.

(Effects of the Invention) As described above, according to the present invention, after the manual valve is switched to the traveling position, the high-speed hydraulic engagement element is initially lubricated and torque is transmitted through the high-speed transmission system, and then the low-speed transmission system is transmitted. It is possible to start the torque transmission through the, and compared with the conventional one that transmits the torque through the low speed transmission system from the beginning of the switching, the rise of the drive torque at the switching of the manual valve becomes gentler, The switching shock is reduced, and the startability is prevented from being deteriorated due to the engagement delay of the low speed hydraulic engagement element.

[Brief description of drawings]

FIG. 1 is a diagram of an example of a transmission to which the present invention is applied, FIG. 2 is a hydraulic circuit diagram thereof, and FIG. 3 is a diagram showing a change characteristic of hydraulic pressure of a hydraulic engagement element at the time of starting. (1) …… Transmission (G1) …… First speed transmission system (low speed transmission system) (G2) …… Second speed transmission system (high speed transmission system) (C1) …… First speed hydraulic clutch (low speed hydraulic engagement element) ) (C2) …… 2-speed hydraulic clutch (high-speed hydraulic engagement element) (7) …… One-way clutch (8) …… Hydraulic source (9) …… Manual valve (10) …… Shift valve (L3) …… 3rd oil passage (oil passage for low speed hydraulic engagement element) (L8) ...... 8th oil passage (oil passage for high speed hydraulic engagement element) (16 ₁ ) ...... Orifice (18) ...... Control valve

Claims (1)

(57) [Claims] 1. A low speed transmission system and at least two high speed transmission systems.
A control device for a hydraulically actuated transmission for a vehicle, comprising a one-step clutch for allowing over-rotation on the output side in the low-speed transmission system, the low-speed hydraulic system establishing the low-speed transmission system. A hydraulic circuit for controlling oil supply and discharge to the engagement element and the high-speed hydraulic engagement element that establishes the high-speed transmission system includes a manual valve that is switchable between at least two positions of a neutral position and a traveling position, and a low-speed position. A shift valve that is switchable to at least two positions, a high speed position, is provided, and the low speed hydraulic engagement element is provided by switching the manual valve to the traveling position, and the high speed hydraulic engagement element at the high speed position via the shift valve. Connecting the high speed hydraulic engagement element to the hydraulic power source when the manual valve and the shift valve are in the traveling position and the low speed position, respectively. An oil passage for Is provided with a control valve switchable between an open position for communicating the oil passage and a closed position for disconnecting the oil passage and discharging oil from the high-speed hydraulic engagement element. The control valve is switched to a closed position when the hydraulic pressure of the element rises to a predetermined pressure, and further, an orifice is provided in an oil passage connecting the low speed hydraulic engagement element to the hydraulic power source at the traveling position of the manual valve. A control device for a hydraulically actuated transmission for a vehicle, wherein the control valve is provided with a side passage in parallel with the orifice communicating with the control valve at a closed position.