JP2531824Y2 - Hydraulic clutch type transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to a hydraulic clutch type transmission that can change the speed without operating a main clutch in a traveling vehicle of a wheel type or a crawler type. Is to improve the feeling of

(B) Prior art The prior application has been filed by the same applicant as the prior art for preventing impact during shifting of a hydraulic clutch type transmission and minimizing the double meshing state of the hydraulic clutch.

For the hydraulic clutch type transmission, see
Japanese Patent Application Laid-Open No. 50-45166 discloses a technique for controlling release of pressure oil at the end of a shift by using pressure oil of a hydraulic clutch for another speed. The technology is known.

(C) Problems to be solved by the invention In the hydraulic clutch type transmission, the first to second speeds,
When the gearshift operation is performed from the third speed to the third speed, in the transition period in which the connection state of one hydraulic clutch is released and the connection of the other hydraulic clutch is started, the pressure on the release side is in a decreasing direction, Pressure is in the rising direction, but if the joining side is joined after the releasing side is completely released, the speed will temporarily decrease during that time, so a shock will occur at the time of joining, and conversely If the release side is still in the semi-jointed state where the pressure still remains, if the complete joining of the joining side is started, both hydraulic clutches will be joined, and the same state as the double meshing state of the gear will occur, and the power transmission loss As a result, the hydraulic pressure of the friction plate of the hydraulic clutch increases sharply, and the friction plate wears severely.

The optimal condition is that the joint side is released and
Ideally, the joining side is completely joined. However, a time lag is inevitably caused in the inflow and movement of the hydraulic oil, and it is necessary to balance the two well.

That is, while the pressure on the release side is decreasing, the pressure on the joining side is in a substantially joined state while the speed of the fuselage has not yet decreased, and the speed is close to the speed on the release side. This means that the shift can be made smooth without creating a speed step.

If the pressure on the release side can be suddenly reduced immediately after the end of the shift succession, the occurrence of the double meshing state can be prevented.

As described above, in the present invention, the releasing side and the joining side are inherited without creating a speed step, and thereafter, the hydraulic pressure on the releasing side is reduced at a stretch.

(D) Means for Solving the Problem The purpose of the present invention is as described above, and a configuration for achieving the purpose will be described below.

In a hydraulic clutch type transmission in which a plurality of hydraulic clutches are disposed on a shift path and a shift is performed by selectively joining the hydraulic clutches, a check valve 2 having a throttle 2a is provided between the hydraulic clutch and a shift control valve V. The check valve 2 opens when the oil flows from the shift control valve V in the direction of the hydraulic clutch, and closes in the opposite direction to act on the throttle 2a.
And an open / close piston 3 that opens and closes the check valve 2 is provided in parallel with the check valve 2, and the hydraulic cylinder portion 3 a of the open / close piston 3 is provided with hydraulic oil for another shift stage hydraulic clutch. And the opening / closing piston 3 is pushed by the rise of the pressure oil of the hydraulic clutch for the gear on the joint side, and the check valve 2 of the hydraulic clutch for the release gear on the release side is opened.

(E) Embodiment The purpose and configuration of the present invention are as described above. Next, the configuration of the embodiment shown in the attached drawings will be described.

FIG. 1 is a power transmission diagram of a hydraulic clutch type transmission showing an embodiment of the present invention, FIG. 2 is a hydraulic circuit diagram, FIG. 3 is a cross-sectional view of a transition period control check valve device A, and FIG. FIG. 5 is a pressure waveform diagram obtained by the conventional delay relief valve D with the unloading valve E, FIG. 5 is also a diagram of a transient period control hydraulic curve according to the conventional configuration, and FIGS. 6 and 7 are transient diagrams according to the embodiment of the present invention. It is a drawing of a period control hydraulic curve.

 This will be described with reference to FIGS. 1 and 2.

In the present embodiment, the first forward clutch F1 and the second forward clutch
Four sets of hydraulic clutch devices, a speed clutch F2, a forward third speed clutch F3, and a reverse speed clutch R, are arranged. By selecting and joining the four sets of hydraulic clutch devices, three forward speeds
The first reverse speed can be changed.

The power from the engine En is input to the input shaft 10 by a V-belt.
This constitutes a high-speed gear meshing auxiliary transmission.

Then, on the hydraulic clutch shaft 12, a forward first speed clutch
An F1 and a third forward clutch F3 are arranged, and a reverse clutch R and a second forward clutch F2 are arranged on the hydraulic clutch shaft 13.

The rotation after shifting is collected by the gears on the shaft 14 by the four sets of hydraulic clutch devices and transmitted to the steering shafts 15 and 15. The steering operation of the fuselage is performed by a steering clutch device and a steering brake device on the steering shafts 15,15.

A deceleration shaft 16 and an axle 17 are arranged downstream of the steering shafts 15,15.

A hydraulic pump P that supplies pressure oil to the hydraulic clutch type transmission of the present invention is disposed at the outer end of the input shaft 10.

As shown in FIG. 2, the pressure oil discharged from the hydraulic pump P passes through the delay relief valve D and the shift control valve V
Refueled.

The delay relief valve D switches from the neutral position for shifting to each shifting position to prevent impact joining when starting,
It is a relief valve to eliminate the dash start of the aircraft.

The pressure oil discharged from the delay relief valve D and the return oil from each hydraulic clutch device are collected, and a low pressure is applied by a low pressure relief valve 18 to be used as lubricating oil for each hydraulic clutch device.

The unload valve E allows the oil to flow into the control piston chamber Da of the delay relief valve D via the throttle Ea.
And a position II for allowing oil to be discharged from the control piston chamber Da without passing through the throttle Ea. When the shift of the shift control valve V is switched, the position is changed to the position II. Thus, the control piston of the delay relief valve D is moved forward from the initial state so as to increase the relief value at all times during shifting.

The delay relief valve D with the unroll valve E is known from Japanese Utility Model Laid-Open No. 58-157049.

In the present invention, as shown in FIG. 2, a transition period control check valve device A, B is interposed between the shift control valve V and the first forward speed clutch F1 and between the second forward speed clutch F2. It is.

In the transition period control check valve device A, the check valve 2 urged by the urging spring 5 is disposed in the valve case 1 in a direction that allows only oil flow from the shift control valve V to the hydraulic clutch.

The check valve 2 is provided with a throttle 2a in front of the check valve 2 for discharging oil from the hydraulic clutch to the shift control valve V.
I try to squeeze by 2a.

Further, an opening / closing piston 3 is arranged in a direction in which the check valve 2 is pushed and opened against the urging spring 5.
Another opening / closing piston 4 is disposed in contact with the back surface of the opening / closing piston 3. A hydraulic cylinder 3a for pushing the opening / closing piston 3 and a hydraulic cylinder 4a for pushing the opening / closing piston 4 are provided. When pressure oil is not supplied to the hydraulic cylinder portions 3a and 4a, the open / close piston 3 is pushed back to the side opposite to the check valve 2 by the biasing spring 6 so as not to protrude toward the check valve 2. It is.

Then, the spring force of the biasing spring 6 is set to the pressure P1 in FIG.

The transition period control check valve devices A and B have the same configuration, but differ in the oil passages connected to the hydraulic cylinder portions 3a and 4a of the open / close pistons 3 and 4 for opening the check valve 2. Is what you do.

As shown in FIGS. 2 and 3, the shift control valve V
In the transition period control check valve device A interposed between the first forward speed clutch F1 and the first forward speed clutch F1, the check valve 2 with the throttle 2a is pressed by the biasing spring 5. When the shift control valve V is selected other than the forward first speed clutch F1, the check valve 2 is closed by the urging spring 5, and the pressure oil is slowly discharged through the throttle 2a.

On the other hand, the oil passage to the forward second speed clutch F2 is in communication with the hydraulic cylinder portion 3a of the opening / closing piston 3, and the oil passage to the forward third speed clutch F3 contacts the back surface of the opening / closing piston 3. The open / close piston 4 communicates with the hydraulic cylinder portion 4a.

Similarly, an oil passage for the third forward speed clutch F3 is interposed between the second forward speed clutch F2 and the shift control valve V, and an oil passage of the third forward speed clutch F3 is connected to the hydraulic cylinder portion 3a of the transition period control check valve device B. 1st-speed forward clutch F1 in cylinder section 4a
The oil passage to the is connected.

Further, a forward first speed clutch F1 and a forward third speed clutch F3 are interposed on the same hydraulic clutch shaft 12, and a forward second speed clutch F2 and a reverse speed clutch R are disposed on a hydraulic clutch shaft 13. Since the oil is separated from the oil passage in the hydraulic clutch shaft by the oil passage separating the seal ring in the seal case provided at the outer end of the same shaft, the oil of the hydraulic clutch on one joint side is The hydraulic oil in the path leaks into the oil path of the other hydraulic clutch on the releasing side, and this hydraulic pressure causes the hydraulic clutch on the releasing side to be in a semi-joined state, whereby the two sets of hydraulic clutches on the same shaft are in the engaged state. Due to rotation. Since heat generation and power loss occur, this problem is released by interposing the opening and closing pistons 3 and 4 to completely release the release-side pressure oil to the drain circuit.

(F) Operation of the Invention With the conventional delay relief valve D with the unloading valve E, the pressure waveform shown in FIG. 4 was obtained. However, when shifting from the forward first speed clutch F1 to, for example, the forward second speed clutch F2, The pressure f1 of the forward first speed clutch F1 drops at a stretch, and the delay relief valve D increases the relief value from the initial state by the unload valve E. Until the pressure P1 was applied, idle running time occurred, and after the aircraft slowed down due to road surface resistance, the forward 2nd speed clutch F2 joined at the pressure P1, so the aircraft was rapidly accelerated and a shift shock occurred. .

Therefore, it is conceivable that the oil discharge of the forward first speed clutch F1 (release side) is controlled by a throttle valve and the forward first speed clutch F1 is increased until the pressure f2 of the forward second speed clutch F2 rises to the pressure P1 as shown in FIG. Is maintained.

However, the pressure f2 of the forward second speed clutch F2 is equal to the pressure P1.
After that, since the first-speed clutch F1 is in a residual pressure state for a long time by the throttle valve, the double meshing state has occurred.

On the other hand, in the case of the present invention, the forward 2-speed clutch is used.
When the pressure f2 on the F2 side reaches the pressure P1, the hydraulic cylinder 3a
And the spring pressure of the urging spring 6 is set so as to correspond to the pressure P1, so that the open / close piston 3 is pressed to open the check valve 2, and the pressure f1 of the forward first speed clutch F1 is reduced to the sixth pressure. As shown in the figure, the pressure is reduced to the state b where the residual pressure is zero.

The same applies when shifting from the second forward speed clutch F2 to the third forward speed clutch F3.

At the time of deceleration, there is no problem about the feeling as much as at the time of increasing the speed, so that it is not configured to operate on the high speed side.

However, with the same configuration, the present invention can be implemented even during deceleration.

In the embodiment shown in FIG. 3, an oil passage 3b is provided at a portion where the opening / closing piston 3 contacts the check valve 2, and when the opening / closing piston 3 contacts the check valve 2, oil is discharged from the throttle 2a. Although the operation is performed through the oil passage 3b, the following operation can be obtained if the oil passage 3b is not provided in the open / close piston.

That is, in FIG. 3, the pressure on the release side intersects with the pressure on the joining side at P1 depending on the diameter of the throttle 2a, but the flow rate control by the throttle diameter is not stable due to the viscosity of oil. And the problem of garbage jams may occur. Then, if it comprises as mentioned above, opening and closing piston 3
Abuts against the check valve 2, no oil is discharged from the throttle 2 a and a back pressure is generated in the check valve 2. The back pressure and the urging force of the urging spring 6 of the opening / closing piston 3 cause the seventh
As shown in the figure, if the release side can be maintained at the pressure P1, the diameter of the throttle 2a does not need to be set so strictly. Then, when the joining pressure becomes equal to or higher than the back pressure of the check valve 2 and the pressure P1 exceeding the biasing spring 6, the opening / closing piston 3 opens the check valve 2 to reduce the residual pressure on the release side to zero.

(G) Effects of the Invention The present invention is configured as described above, and has the following effects.

First, in the hydraulic clutch type transmission, the open / close piston 3 is pushed to open the check valve 2 and the pressure of the release-side shift speed hydraulic clutch is immediately reduced to the state of zero residual pressure as shown in FIG. Thus, it is possible to eliminate the shackle state that occurs when the gear is shifted and the release side is released before the connection side is joined, and the speed is once reduced, and the shock is caused by the impact connection. In addition, the interlocking of the check valve 2 and the opening and closing pistons 3, 4 allows the connection / disengagement to be inherited at a well-balanced speed.

Secondly, since the double meshing between the hydraulic clutch on the release side and the hydraulic clutch on the joining side can be eliminated, the power loss and heat generation caused by the double meshing state can be eliminated. is there.

[Brief description of the drawings]

FIG. 1 is a power transmission diagram of a hydraulic clutch type transmission showing an embodiment of the present invention, FIG. 2 is a hydraulic circuit diagram, FIG. 3 is a cross-sectional view of a transition period control check valve device A, and FIG. FIG. 5 is a pressure waveform diagram obtained by the conventional delay relief valve D with the unloading valve E, FIG. 5 is also a diagram of a transient period control hydraulic curve according to the conventional configuration, and FIGS. 6 and 7 are transient diagrams according to the embodiment of the present invention. It is a drawing of a period control hydraulic curve. A, B ...... Transition period control check valve device D ...... Delay relief valve V ...... Shift control valve F1 ...... Forward first speed clutch F2 ...... Forward second speed clutch F3 ...... Forward third speed clutch R ...... Reverse speed clutch f1 ... Hydraulic curve of forward first speed clutch f2 ... Hydraulic curve of forward second speed clutch

Continuation of the front page (56) References JP-A-51-12778 (JP, A) JP-A-50-45166 (JP, A) JP-A-47-40720 (JP, A) , U) JP-B-57-17226 (JP, B2) JP-B-58-25175 (JP, B2) JP-B-57-20504 (JP, B2)

Claims (1)

(57) [Scope of request for utility model registration] 1. A hydraulic clutch type transmission device in which a plurality of hydraulic clutches are disposed on a shift path and a shift is performed by selectively joining the hydraulic clutches, wherein a throttle 2a is provided between the hydraulic clutch and a shift control valve V. A check valve 2 which opens when oil flows from the shift control valve V in the direction of the hydraulic clutch, closes in the opposite direction, and is interposed with the check valve 2 in which the throttle 2a acts. An open / close piston 3 for opening and closing the check valve 2 is provided, and pressure oil to another shift speed hydraulic clutch is guided to a hydraulic cylinder portion 3a of the open / close piston 3 so that the shift speed hydraulic clutch on the connection side is provided. A hydraulic clutch-type transmission, wherein the opening and closing piston 3 is pushed by the rise of the pressure oil to open the check valve 2 of the release-side hydraulic clutch for the shift stage.