JPH064106Y2 - Hydraulic clutch type transmission - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial field of application The present invention, in a hydraulic clutch type transmission, eliminates the impact when the hydraulic clutch is switched during gear shifting and the power transmission gear train is switched, and smooth gear shifting is possible. It is what

(B) Conventional Technology A number of technologies related to the hydraulic clutch type transmission have been conventionally known by the present applicants.

For example, it is as in Japanese Utility Model Laid-Open No. 53-114128.

(C) Problems to be solved by the invention However, even in the conventional technology, when shifting from the first forward speed to the second forward speed and from the second forward speed to the third forward speed, pressure oil is supplied from the cylinder of the hydraulic clutch at the preceding stage. Is released and becomes non-engaged, pressure oil flows into the hydraulic clutch of the next stage, and the speed temporarily decreases during the transitional period when it is in the engaged state, and then a shock such as a sudden dash during shifting is generated. The present invention eliminates the shock of a sudden decrease in speed and a sudden start in the transition period.

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

In a configuration in which a gear shift is performed by selectively joining hydraulic clutches provided for each gear train to a plurality of continuously meshed gear trains, the pressure oil of the hydraulic clutch to be joined at the time of gear shifting is applied to the oil chamber 3d at one end. A shift transition period control spool 3 that causes the pressure oil of the disengagement side hydraulic clutch to act on the oil chamber 3a side at the other end is provided, and the disengagement side oil chamber 3a communicates with the drain circuit D through the throttle hole 3c. As the shift transition period control spool 3 moves due to the increase in pressure on the joining side, the throttle throttle hole 3c is further narrowed, and the throttle at the position where the pressure in the oil chamber 3d on the joining side and the pressure on the releasing side substantially match. The oil chamber 3a is configured to directly communicate with the drain circuit D without passing through the hole 3c.

(E) Embodiment The purpose and structure of the present invention are as described above, and the structure for achieving the purpose will be described below.

FIG. 1 is a skeleton diagram showing an embodiment of a hydraulic clutch type transmission.

The power from the engine E is transmitted to the input shaft 20 by a belt, and the power is transmitted between the input shaft 20 and the counter shaft 21 by 4
It is possible to shift gears in steps.

A hydraulic pump P is attached to the projecting portion of the input shaft 20 outside the transmission case.

By disposing the two hydraulic clutch shafts 22 and 23 below the four-stage auxiliary transmission and selectively engaging the hydraulic clutches F1, F2, F3, and R on the spool 2 of the transmission valve, , 3rd forward and 1st reverse.

The hydraulic clutch type transmission unit collects the rotation after shifting to the deceleration shaft 24, and passes the left and right steering clutches on the steering shaft 25.

The rotation that has been interrupted for steering by the steering shaft 25 is transmitted to the axle shaft 17 via the final shaft 16.

FIG. 2 is a drawing showing the state of curve a in FIG. 4 of the movement of the shift transition period control spool 3 when shifting from forward first speed to second speed, and FIG. 3 is the same as curve b in FIG. FIG. 4 is a drawing showing a state, FIG. 4 is a drawing showing a hydraulic pressure curve at the time of shifting from the first forward speed to the second speed, and FIG. 5 is a diagram showing the movement of the shift transition period control spool 3 at the time of shifting from the second forward speed to the third speed. Of which, curve a in FIG. 7
6 is a drawing showing the state of curve b, and FIG. 7 is a drawing of the hydraulic pressure curve when shifting from the second forward speed to the third speed.

Only in FIG. 1, the configuration of the slow pressure increasing valve D is disclosed in the circuit of the hydraulic pump P, but it is omitted in other drawings.

Due to the configuration of the slow pressure increase valve D and the pressure return valve 7, the pressure oil on the joining side always rises gradually from the pressure 0 at the time of shifting.

That is, the pressure return valve 7 is arranged at the portion of the throttle hole 9 opened in the back chamber of the spring receiving spool 8 of the slow pressure increase valve D, and the valve always opens when the shift valve 2 is switched. The pressure return valve 7 is opened by the pin 2a,
Since the pressure oil in the back chamber of the spring receiving spool 8 communicates with the drain circuit D, the spring receiving spool 8 is fully retracted, and the slow pressure increasing valve D is easily opened. As shown in the figure, it always starts from 0.

After the shift operation of the shift valve 2 is completed, the opening pin 2a
Is retracted, the spring receiving spool 8 is gradually returned by the pressure oil from the throttle hole 9, the slow pressure increasing valve D is pushed to close the drain circuit D circuit, and the pressure is gradually increased.

The slow pressure increase valve D thus configured is configured in the circuit of the hydraulic pump P. L is a relief valve and l is a lubricating oil circuit.

In such a structure, the present invention further includes the transmission valve 2
And a disengagement side port A that communicates with the return oil circuit of the disengagement side hydraulic clutch.

As shown in FIG. 2, FIG. 3, FIG. 5, and FIG. 6, the shift transition period control spool 3 is arranged in the valve case 5 to form a shift transition period control valve.

The shift transition control spool 3 is slidable right and left within the valve case 5, and the pump port P1 is constantly pressed by the biasing spring 4.

Further, a pump port P1, a detachment side port A, and a drain circuit D are opened in the valve case 5.

In the case of FIG. 2, FIG. 3, and FIG. 4, the pump port P1
Communicates with the hydraulic pump P and the hydraulic clutch F2 on the joint side,
The disengagement side port A communicates with the disengagement side hydraulic clutch F1.

In the state of the curve a in FIG. 4 shown in FIG.
When the speed change valve 2 is switched from the second speed to the second speed, the return oil in the hydraulic clutch F1 enters the disengagement side port A, and the pass portion 3b.
By further reaching the throttle hole 3c through the oil hole 3a, the pressure gradually decreases as shown by the curve a.

At the same time, the pressure in the hydraulic clutch F2 starts to gradually rise, pressure oil enters the oil chamber 3d, and the shift transition period control spool 3 gradually moves to the right.

As the shift transition control spool 3 moves to the right,
In the throttle hole 3c, the aperture gap is further narrowed, and the curve a in FIG.
The slope becomes gentle like the end of the.

Then, with the shift transition control spool 3 moving to the right,
As shown in FIG. 3, the aperture hole 3c is completely squeezed, and then the pass portion 3b communicates with the drain circuit D.
The pressure of the hydraulic clutch F1 decreases linearly as indicated by a curve b.

In the present invention, as shown in FIG. 4, the biasing spring 4 is provided so that the pressure on the pump port P1 side where the pass portion 3b opens to the drain circuit D and the pressure Pa on the release side port A side become the same. To adjust. By configuring the joining pressure of the joining side hydraulic clutch to be in the vicinity of the upper side of the pressure Pa, the joining side hydraulic clutch is completely joined after the releasing side hydraulic clutch is completely released. It is possible.

Next, referring to FIG. 5, FIG. 6, and FIG. This state shows the state of shifting from the second forward speed to the third speed,
In this case, the hydraulic clutch F3 is attached to the pump port P1.
And the hydraulic pump P communicate with each other, and the disengagement side port A communicates with the hydraulic clutch F2.

Also in this case, the seventh gear is almost the same as the case of the first to second forward gears.
The two hydraulic clutches are switched by drawing a hydraulic curve as shown in the figure.

On the contrary, when switching from the third forward speed to the second speed, the return oil of the hydraulic clutch F3 communicates with the drain circuit D as it is, so that the hydraulic oil immediately descends, and the hydraulic oil on the hydraulic clutch F2 side shifts to the control spool 3 in the shift transition period. Regardless of this, the slow pressure increase valve D gradually increases from 0, so that the welding starts gradually from the position where the welding side has a low pressure, and the deceleration shift is performed without giving an impact deceleration state such as engine braking. Is what you can do.

Similarly, in the case of shifting from the second forward speed to the first speed, the hydraulic clutch F2 directly communicates with the drain circuit D, so that the speed suddenly becomes 0, and since the shift transition period control spool 3 has no effect, the slow pressure increase valve D As a result, the pressure oil of the hydraulic clutch F1 gradually rises from 0, and deceleration shifting can be performed without impact.

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

First, at the time of speed-up gear shifting, the pressure of the hydraulic clutch on the disengagement side gradually decreases through the throttle hole 9 until the pressure of the hydraulic clutch on the joining side reaches the pressure on the disengagement side, and the two agree. At that time, the pressure on the disengagement side suddenly becomes 0, so that the two hydraulic clutches are smoothly switched,
It was possible to eliminate the impact at the time of joining.

Secondly, in the case of deceleration shifting, the disengagement side is lowered at a stroke and the joining side is gradually raised from a pressure of 0 by the slow pressure increase valve D, so that the impact due to engine braking during deceleration can be eliminated. It was made.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an embodiment of a hydraulic clutch type transmission, and FIG. 2 is a curve a in FIG. 4 showing the movement of the shift transition period control spool 3 when shifting from forward first speed to second speed. 3 is a drawing showing the state of the curve b in FIG. 4, FIG. 4 is a drawing showing the hydraulic pressure curve during shifting from the first forward speed to the second speed, and FIG. Of the movement of the speed change transition control spool 3 during the speed change from the third speed to the third speed,
6 is a drawing showing the state of the curve a, FIG. 6 is a drawing showing the state of the curve b, and FIG. 2 ... Gear shift valve 2a ... Open pin 3 ... Gear shift transition period control spool 3a ... Oil hole 3b ... Pass section 3c ... Throttle hole 3d ... Oil chamber 4 ... Energizing spring 7 ... Pressure return valve 8: Spring receiving spool 9: Throttle hole

Claims (1)

[Scope of utility model registration request] 1. In a structure in which a plurality of constantly meshed gear trains are connected by selectively connecting hydraulic clutches attached to the respective gear trains, the pressure oil of the hydraulic clutch on the side to be connected at the time of gear changeover is A shift transition period control spool 3 is provided which acts on the oil chamber 3d and causes the pressure oil of the disengagement side hydraulic clutch to act on the oil chamber 3a side at the other end, and the disengagement side oil chamber 3a is drained through the throttle hole 3c. As the shift transition period control spool 3 is moved by communicating with the circuit D and the pressure on the joining side increases, the throttle hole 3c is further throttled, and the pressure in the oil chamber 3d on the joining side and the pressure on the releasing side substantially match. The hydraulic clutch transmission is characterized in that the oil chamber 3a is directly communicated with the drain circuit D at the position without passing through the throttle hole 3c.