JPH0612312Y2 - Hydraulic clutch type transmission - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial field of application The present invention relates to a wheel-type or crawler-type traveling vehicle for increasing the speed of a hydraulic clutch type transmission that can change the speed without operating the main clutch. It is intended to improve the feeling during shifting and deceleration shifting.

(B) Prior Art The same applicant has previously filed a technique for preventing impact joining at the time of increasing speed of a hydraulic clutch type transmission.

Conventionally, a transition period control check valve was provided to smooth the shift when the hydraulic clutch type transmission increased in speed, and conversely, the transition period control check valve was provided to smoothly shift when decelerating. In the former case, on the contrary, the acceleration suddenly changes during deceleration to generate a shock, and in the latter case, on the contrary, a shock occurs during acceleration.

(C) Problems to be solved by the invention When the gear shift operation is performed in the hydraulic clutch type transmission, the hydraulic clutch that was joined in the previous stage is released,
During the transitional period when the connection of the hydraulic clutch in the latter stage is started, the pressure on the release side is in the decreasing direction and the pressure on the connection side is in the increasing direction.

In this case, at the time of increasing the speed, if the joining side starts joining after the releasing state of the releasing side progresses, the speed will once decrease during the transition period, so that a jerk and an impact state occur.

Further, at the time of deceleration, the joining side joins at a low pressure, so if the releasing side continues to join the two, the two become joined and a shock is generated in this case as well.

As described above, the conditions for the occurrence of the impact due to the speed reduction during the shift are different between the speed increase and the deceleration.

In the prior art, a transitional period control valve is provided in order to eliminate the impact that occurs mainly during acceleration or deceleration.

However, impacts during gear shifting similarly occur on the deceleration side and the acceleration side that are not considered, and the present invention proposes to release the hydraulic clutch on the non-considered side of the hydraulic clutch type transmission. The hydraulic clutch on the joining side is switched smoothly so that no impact is generated during shifting.

However, during acceleration and deceleration, the direction of acceleration differs due to the difference in the force that pulls the aircraft to accelerate it and the braking force that causes it to stop, so the same transient control valve can be used for both acceleration and deceleration. It is impossible to actuate to remove the shock.

In the present invention, the structure of the transient control valve is improved so as to operate so as to remove the impact during acceleration and deceleration.

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

In a hydraulic clutch type transmission in which a plurality of hydraulic clutches are arranged on a speed change path and a speed change is performed by selectively connecting the hydraulic clutches, a transition period control valve is provided between the hydraulic clutch and the speed change control valve V, and the transition period control valve is provided. Period control valve,
A control spool with a throttle that reduces the amount of return oil from the hydraulic clutch, and a control piston that blocks movement of the control spool in the closing direction due to return oil, the control piston being capable of abutting one end on the control spool, Into the oil chamber at the other end, the pressure oil of the clutch port at the low speed gear stage is introduced through the oil passage.

(E) Embodiment The structure and purpose of the present invention are as described above. Next, the structure of the embodiment shown in the accompanying 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 the same hydraulic circuit diagram, and FIG. 3 is a transient control valve V arranged on the upper surface of a transmission case.
1, V2, V3 are plan sectional views, FIG. 4 is a sectional view showing the operating portion of the hydraulic valve device V, and FIG.
It is drawing which shows the change of the pressure oil curve in 3rd speed.

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

In this embodiment, four sets of hydraulic clutches including a forward first speed clutch Fc1, a forward second speed clutch Fc2, a forward third speed clutch Fc3, and a reverse speed clutch R are arranged and the four hydraulic clutches are arranged.
By selectively connecting a pair of hydraulic clutches, it is possible to change the speed to three forward speeds and one reverse speed.

The power from the engine E is input to the input shaft 10 by the V-belt, and between the input shaft 10 and the counter shaft 11, 4
It constitutes a high speed gear mesh type auxiliary transmission device.

Then, the forward first speed clutch Fc is mounted on the hydraulic clutch shaft 12.
1 and the forward third speed clutch Fc3 are arranged, and the reverse speed clutch R and the forward second speed clutch Fc2 are provided on the hydraulic clutch shaft 13.
And are arranged.

The four sets of hydraulic clutches collect the rotation after shifting to the gear on the shaft 14 and transmit it to the steering shaft 15. Steering axis 1
The steering clutch device and the steering brake device above 5, 5 are used to perform the steering operation of the airframe.

A reduction shaft 16 and an axle 17 are arranged at the rear stage of the steering shafts 15, 15.

A hydraulic pump Po for supplying pressure oil to the hydraulic clutch type transmission of the present invention is arranged at the outer end of the input shaft 10.

As shown in FIG. 2, the pressure oil discharged from the hydraulic pump Po is sent to the shift control valve V via the delay relief valve DRV.

The delay relief valve DRV prevents impact joining when switching from the shift neutral position to each shift position and starting.
It is a relief valve to eliminate the dash of the aircraft.

An oil passage hole 30a for hydraulically sliding the spool 30 of the delay relief valve DRV is formed. The initial peak pressure k of the pump port is generated due to the diameter of the oil passage hole 30a.

The pressure oil discharged from each delay relief valve DRV and the return oil from each hydraulic clutch are collected, a low pressure is given by the low pressure relief valve 18, and the oil is sent to the lubricating oil passage 19 of each hydraulic clutch device. .

The unload valve E causes an oil inflow to the control piston chamber Da of the delay relief valve DRV via the throttle Ea, and a position I to discharge oil from the control piston chamber Da without the throttle Ea. The control piston of the delay relief valve DRV is always in the initial pressure 0 state at the time of the gear shifting operation so that the gear shift control valve V has the II position when the gear shifting control is performed and moves to the I position at the end of the gear shifting. It is for operating to increase the relief value.

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

In the present invention, the transition control valves V1, V2 and V3 are arranged between the speed change control valve V and each forward hydraulic clutch in the above-described overall structure.

As disclosed in FIG. 4, the hydraulic control unit of the hydraulic clutch type transmission of the present invention is arranged on the mission case as a three-stage structure.

A delay relief valve D is provided in the uppermost valve case 3.
An RV and an unload valve E are arranged, a shift control valve V is arranged in an intermediate valve case 2, and a transition period which constitutes a main part of the present invention is arranged in a lower valve case 1. Three sets of control valves V1, V2 and V3 are arranged. In FIG. 3, the transient control valves V1, V2, V3 arranged in the lower valve case 1 are shown.
Is shown.

Further, as shown in FIG. 4, a speed change operation pin 22 and a speed change operation shaft 23 for operating the spool of the speed change control valve V are arranged in a space penetrating the valve cases 2 and 3, and the speed change operation shaft 23 is The gear shift operation lever 24 is projected to a portion of the valve case 3 which is projected to the outside.

The delay relief valve DRV formed inside the valve case 3 and the speed change control valve V formed inside the valve case 1 and the valve case 2 are the techniques disclosed by the applicant in the prior application, and thus the details will be omitted. Omitted explanations.

However, the configuration is such that the switching oil passage shown in the hydraulic circuit diagram of FIG. 2 is configured, and switching is performed in each case.

Next, referring to FIG. 3, the transition control valves V1, V2, V
The configuration of No. 3 will be described.

In the transitional period control valve V1, a biasing spring 8, a spring receiver 6 and a first speed control spool 5 are fitted in the hole of the lower valve case 1. A land 7 is formed on the first speed control spool 5, and a throttle hole 9 is opened through a part of the land 7.

In the transitional period control valve V2, a biasing spring 28, a second speed control piston 26, and a second speed control spool 25 are fitted in the hole of the lower valve case 1. A land 27 is formed on the second speed control spool 25, and a throttle hole 29 is formed so as to penetrate the land 27.

The transient control valve V3 has a biasing spring 38, a third speed control piston 36, and a third speed control spool 35 arranged in a hole of the lower valve case 1, and the third speed control spool 35 is provided.
A land 37 is formed on the above-mentioned land 37, and a diaphragm hole 39 is opened through the land 37.

In the configuration described above, the forward first speed valve port f1 is selected from the forward first speed clutch port F1 and the forward first speed valve port f1 which are switched by the first speed control spool 5, and the second speed control piston 26 of the transient control valve V2 is connected to the forward speed first speed valve port f1. An oil passage a communicates with the chamber to be pressed.

Similarly, of the forward 2nd speed clutch port F2 and the forward 2nd speed valve port f2 that the 2nd speed control spool 25 switches, the forward 2nd speed valve port f2 and the transition period control valve V3 3 are selected.
The chamber on the pressing side of the speed control piston 36 is communicated with the oil passage b.

D shown as the other port in FIG. 3 is a drain port.

(F) Operation of the invention The structure of the invention is as described above. Next, the operation of the invention will be described.

When increasing the speed from the 1st speed to the 2nd speed, the traction force of the vehicle needs to be generated by the engagement of the hydraulic clutch. The speed increasing joint region c shown in FIG. 5 is located in the high pressure region of the hydraulic curve.

Therefore, if the connection state of the low speed side hydraulic clutch is not maintained until the high speed side hydraulic clutch is connected, once the low speed side hydraulic clutch is disengaged and the speed decreases, finally the high speed side As a result of joining, the acceleration becomes negative during that time, and a shocking state occurs.

Therefore, when increasing speed, the pressure on the low speed side is maintained as long as possible, and the pressure on the low speed side hydraulic clutch is completely released near the end position of the speed increasing joint area c where the high speed side is completely joined. It constitutes part n.

On the other hand, on the deceleration side, there is no need to pull the vehicle,
On the contrary, since the braking force is applied depending on the weight of the machine body and the road surface condition, the curve of the hydraulic clutch on the low speed side, which is decelerating, is joined in the low pressure region. Therefore, the deceleration joint area d is at a low position of the hydraulic curve, and if the high speed hydraulic clutch is also engaged after the low speed hydraulic clutch is engaged, a double meshing state occurs, and the high speed side is disconnected from the state. Immediately after that, the engine speed is regulated to the low speed side, and the engine brake state is generated. In this case, negative acceleration is also generated, and the operator on board gets a shock.

In the present invention, when decelerating, the high speed side is disengaged early, the inertial force is set to the idle state, and the low speed side hydraulic clutch is gradually joined to match the low speed side hydraulic clutch. To prevent the generation of negative acceleration.

Next, returning to FIG. 2 and FIG. 3, the operation is shown for each speed of the embodiment.

When entering the first speed from the neutral position, the pressure oil flowing into the first forward speed valve port f1 is controlled by the delay relief valve DRV to initially form the initial peak pressure k, but thereafter gradually increases. Since the curve is formed, the forward first speed clutch Fc1 is gradually engaged, and the shock starting state does not occur.

That is, in the transitional period control valve V1, the forward first speed valve port f1 is previously moved by the biasing spring 8 to the first forward speed clutch port F1.
The first speed control spool 5 is pushed to the open position, and the land 7 is disengaged to the forward first speed clutch port F1 side. Therefore, the pressure oil of the first forward speed valve port f1 flows into the first forward speed clutch port F1 without receiving any resistance. After that, when the hydraulically actuated cylinder of the first forward speed clutch Fc1 is filled with pressure oil, the first forward speed valve port f1
And the hydraulic pressure in the first forward speed clutch port F1 becomes equal, but the pressure receiving area of the land 7 on the first forward speed valve port f1 side is smaller than the area of the land on the first forward speed clutch port F1 side. The control spool 5 slides to the right in the drawing, and the land 7 closes the gap between the first forward speed valve port f1 and the first forward speed clutch port F1.

Next, when the speed is increased from the first forward speed to the second speed, the transition period control valve V2 is pressed by the pressing force of the biasing spring 28 and the pressure oil flowing into the second forward speed valve port f2 so that the land 2 moves.
7 is open in the direction of disengagement, and the pressure oil of the second forward speed valve port f2 flows into the second forward speed clutch port F2 without any resistance. Therefore delay relief valve DRV
The pressure rises along the curve of the pressure oil controlled by. When the hydraulically actuated cylinder of the forward second speed clutch Fc2 is filled with the pressure oil, as in the case of the first speed control spool 5 described above,
The speed control spool 25 slides to the right in the drawing, and the land 27 closes the gap between the forward second speed valve port f2 and the forward second speed clutch port F2.

The return oil from the forward first speed clutch port F1 pushes the land 7 of the first speed control spool 5 against the biasing spring 8 and the forward first speed valve port f1 is opened to the drain side by the speed change control valve V. Since the speed control spool 5 is pushed back and the land 7 is closed and flows out only from the throttle hole 9 provided in the land 7, the pressure at the first forward speed clutch port F1 gradually decreases. As a result, the pressure on the first forward speed clutch port F1 side is maintained only during the increased speed joining region c, and the semi-engaged state of the first forward speed clutch Fc1 is maintained.

When the return oil in the first forward speed clutch Fc1 is near the end, the pressure on the return oil side decreases, the urging force of the urging spring 8 wins, and the land 7 is pushed in the opening direction to be released. The pressure in the forward first speed clutch Fc1 forms the pressure decreasing step portion n at which the pressure decreases.

Next, when increasing the speed from the second forward speed to the third speed, the third speed control spool 35 pushes the land 37 by the biasing spring 38 and the pressing force of the pressure oil flowing into the third forward speed valve port f3. 37 is opened, and the inflow of the pressure oil from the third forward speed valve port f3 to the third forward speed clutch Fc3 is performed without any resistance. When the hydraulically actuated cylinder of the forward third speed clutch Fc3 is filled with pressure oil, the third speed control spool 35 slides to the left in the drawing, similar to the first speed control spool 5 described above, and moves forward with the forward third speed valve port f3. The land 37 closes the space between the third speed clutch port F3.

The return oil from the forward second speed clutch port F2 is 2
The land 27 of the speed control spool 25 is pressed against the biasing spring 28 to move it to the closing side, and the return oil thereafter flows out through the throttle hole 29 and gradually flows out. That is, the semi-engaged state of the forward second speed clutch F2 is maintained.

Then, in the final stage of the return oil from the second forward clutch Fc2, the urging spring 28 overcomes the pushing force of the return oil on the land 27, so that the land 7 is released to form the pressure lowering step portion n.

Next, at the time of deceleration from the third forward speed to the second speed, the second speed control spool 25 of the transitional period control valve V2 operates with the force of the urging spring 28 after the return oil of the second forward speed clutch Fc2 has been discharged. , The land 27 returns to the opening direction by the pressure oil flowing into the second forward speed valve port f2, and the second forward speed valve port f
The second pressure oil flows into the second forward speed clutch port F2 without resistance.

On the other hand, the return oil from the forward third speed clutch port F3 is
Since the accommodation chamber of the urging spring 38 and the forward second speed valve port f2 are connected by the oil passage b, the third speed control piston 3
A force for pushing 6 to the right in the drawing acts to push the land 37 by the force of the return oil from the forward third speed clutch port F3, but the pressure pushing the third speed control piston 36 is larger, so the land 37 is opened. The return oil of the forward third speed clutch port F3 flows out to the drain circuit all at once, and at the initial stage of the deceleration joint area d, the third forward speed clutch port F3.
The pressure of is reduced. This draws the steep drop curve m in FIG.

Even when decelerating from the second forward speed to the first speed, pressure oil from the first forward speed valve port f1 to the first forward speed clutch port F1 is urged by the biasing spring 8 to press the first speed control spool 5 to the open side. Also, the land 7 is opened by the pressure oil flowing into the first forward speed valve port f1 and flows in without resistance.

On the other hand, in the transition period control valve V2, the return oil from the forward second speed clutch port F2 pushes the land 27 of the second speed control spool 25, but the pressure oil of the forward first speed valve port f1 is stored in the accommodating chamber of the biasing spring 28. Since it is flowing in through the oil passage a, this pressure pushes the second speed control spool 25 to a position where the land 27 is opened, and the forward second speed clutch port F
The second pressure oil is also spilled all at once. This constitutes the steep drop curve m in FIG.

(G) Effect of the Invention Since the present invention is configured as described above, it has the following effects.

First, by interposing the transitional period control valves V1, V2, V3, the valves determine whether the valve is speeding up or decelerating, and the pressure oil curve of the releasing side hydraulic clutch is lowered as specified. Therefore, by engaging the hydraulic clutch on the joining side in conformity with this, gear shifting can be performed without impact during acceleration and deceleration.

Secondly, during deceleration, the low speed side is joined after releasing the high speed side hydraulic clutch, and the double meshing state of both hydraulic clutches does not occur, resulting in friction plate wear and lubricating oil temperature change. No rise will occur.

[Brief description of drawings]

FIG. 1 is a power transmission diagram of a hydraulic clutch type transmission showing an embodiment of the present invention, FIG. 2 is the same hydraulic circuit diagram, and FIG. 3 is a transient control valve V arranged on the upper surface of a transmission case.
1, V2, V3 are plan sectional views, FIG. 4 is a sectional view showing the operating portion of the hydraulic valve device V, and FIG.
It is drawing which shows the change of the pressure oil curve in 3rd speed. V1, V2, V3 ... Transition period control valve F1 ... Forward first speed clutch port F2 ... Forward second speed clutch port F3 ... Forward third speed clutch port 5, 25, 35 ... Control spool 26, 36 ... Control Piston 7,27,37 ... Land 8,28,38 ... Biasing spring 9,29,39 ... Throttle hole V ... Shift control valve

Claims (1)

[Scope of utility model registration request] 1. A hydraulic clutch type transmission in which a plurality of hydraulic clutches are arranged on a speed change path and a speed change is performed by selectively connecting the hydraulic clutches, wherein a transition period control valve is provided between the hydraulic clutch and the speed change control valve V. Is provided, the transitional period control valve is constituted by a control spool with a throttle that throttles the amount of return oil from the hydraulic clutch, and a control piston that blocks movement of the control spool in the closing direction by the return oil. A hydraulic clutch transmission in which one end can be brought into contact with a control spool, and pressure oil from a clutch port at a low speed shift stage is introduced into an oil chamber at the other end through an oil passage.