JPS6252254A - Pressure control mechanism for hydraulic clutch - Google Patents

Abstract

PURPOSE:To reduce a shock when a speed change is performed, by providing two valve mechanisms and throttle valves to be rationally arranged and constituting the throttle valve so that its acting time is changed. CONSTITUTION:A pressure control device D is constituted by parallelly arranging the first valve mechanism 21 switched to a block condition if a pilot pressure from the side of an oil hydraulic clutch reaches a predetermined value, the second valve mechanism 22 switched to a communicating condition if the above described pilot pressure reaches the predetermined value and throttle valves 20, and said pressure control device D is correlated interlocking to a subtransmission B so that a quantity of oil decreases if the subtransmission B is controlled to a high speed side. In this way, even if a work truck, when it is in high speed running, provides large running resistance with a large speed down when a speed change is performed, the truck, controlling the hydraulic clutch for a longer time and enabling a half-clutch condition to be increased, can reduce a shock when the speed change is performed.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a pressure control mechanism for a hydraulic clutch.
- Regarding the hydraulic branch j-rj for slowly operating the clutch.

[Conventional technology]

To add a 111N hydraulic clutch for gear shifting to the work t1f, for example, as shown in Japanese Patent Application Laid-Open No. 59-103059, a multi-plate i (hydraulic clutch of 1'7) is installed in 7 series with respect to the traveling transmission system. Along with Jru, it is linked to the operation of the transmission mechanism for Chemical 1-■.
I installed the valve to make it easier, and there is a valve 1);

[Problems to be solved by the invention] However, U7, as in the above cited example, if a valve is simply provided to operate the hydraulic clutch, the supply of water to the hydraulic clutch when the hydraulic clutch is engaged is limited. Because the IE force of the hydraulic oil rises in a very short time,
- Clutch engagement is performed rapidly, causing shock1
1-There is a problem.

Therefore, it is conceivable to interpose a throttle valve in the oil passage for supplying hydraulic oil to reduce the pressure of the hydraulic oil supplied to the hydraulic clutches, but it is also possible to Not only does this cause the problem of slow operation across the entire range, but the throttle valve also acts when the hydraulic clutch is engaged, so if a leak occurs in the engaged hydraulic clutch, the clutch may slip. It becomes easier to solve another problem by 11 and 4.

Also, as an example of a work vehicle, when an agricultural vehicle is lowered 4 times, the wheels sink into the soft ground.7. When shifting at a running speed of 3 according to the above-mentioned reference structure in a state where the gear is loaded, the resistance from the ground is large, so even if the tJI of the hydraulic clutch is There is a problem that the speed drop of the Φ body at ☆ speed in the range is large, and the shock that occurs when the hydraulic clutch is engaged tends to be large.

According to the present invention, 1. The rational arrangement of the hydraulic mechanism allows for running against the work vehicle. The point is to reduce the stress.

[Failure to solve the problem]

Features of the present invention include: 1. A main transmission device configured with multiple stages;
The traveling transmission system consists of an auxiliary transmission with two stages, high and low, and a hydraulic cranometer that intermittents the shifted power. When the first pressure reaches a predetermined value, the first valve mechanism switches from the communicating state to the closed state, and when the pi c + nol - pressure from the hydraulic clutch side reaches a value greater than the predetermined value, the first valve mechanism switches from the closed state to the closed state. The second switch to the communication state
11 units consisting of a valve mechanism and a throttle valve arranged in parallel
When the auxiliary transmission is operated to the high speed side by interposing the 1-finger device, the amount of power per unit time supplied through the pressure control device is increased when the auxiliary transmission is operated to the low speed side. The sub-transmission device and the pressure canine 1-11-le device are linked to reduce the amount of pressure compared to the case where the pressure is reduced.

[For production]

If the above characteristics are configured as shown in Fig. 1, for example, when operating the main transmission (8) with the sub-transmission (1) set to the low speed side (:[, Fig. 4 As shown in the operating time range (toA) and (tO) of the graph, the pressure in the oil passage (25) for the hydraulic clutch (3) is slowly increased through the throttle valve (20), and then 2-valve mechanism (
22) is brought into communication, the pressure is quickly applied as shown in the action time range (tv2).

Also, with the sub-transmission (B) set to the high speed side, -
1-Weird i! When operating the i-equipment w (A), as shown in the operating time range (to) of the graph in Fig. 5, the oil passage (20
) will continue to rise for a longer period of time than in the case where the auxiliary transmission (D) is set to the low speed side as described above.

In addition, the action area (toe) of the graph indicated by the broken line in the figure is the oil passage (25) immediately after starting the vehicle engine.
This phenomenon occurs when the transmission is operated to the first forward speed, and the pressure control device (1) is connected to the logic valve group (1).
24), it is a characteristic curve that appears every time the gear is changed.

Also, the time range (toA) in which the throttle valve (20) acts;
The reason why the graph is curved at (to) is that an accumulator (26) is provided in the oil passage (25).

〔Effect of the invention〕

Therefore, two valve mechanisms and a throttle valve can be rationally arranged.
Okay, ka-), change the action delay time of the 1 riri valve 31
, 11-line ++ (if the resistance is large or the gear shift is moderately down or large, the throttle valve should be set to 11). 11!'
□R oil I+"/ '/) It saves you time to make 1,000 works, so you can stay in the so-called half-clutch state for a long time.
), II, II, I can reduce the noise during gear shifting.
(3I sea urchin change during continuous running i1i running jj continuous + i da 1'
Even when the non-speed ratio is small, a suitable half-)7,000 state can be obtained (ν), making it possible to reduce the shift and one shift during gear shifting.

〔Example〕

Embodiments of the present invention are shown in the drawings below. (I will explain next.

In Fig. 2, the φj1 force from the engine (1) is transferred to -1 through the clutch (2): the transmission (^),
Multi-plate type Ura V1 club, -1 (3), opening degree i! Equipment (1
Thu) It is transmitted to the front/reverse switching device 1'f (C), and the power is transferred from the forward/reverse switching device (to) the rear wheels (4).
4 to the y-ΦJ1 device (4a), and also from the forward/reverse switching device (C) to the minute+LQ signal 1! Tariyamauchi, 1)
; Difference φ applied to one wheel (5)) λ transmitted to one device (5a)
J, constitute a traveling transmission system, ■, the -i clutch (
2) Change the power transmitted through i! device (E)),
On the other hand, the rotary clutch (7) is configured to sequentially transmit the force to the external φ1j force extraction 7 axis (F)) to form the 1st φ11 system of a four-wheel drive agricultural tractor.

The main transmission (A) has two synchronized L
It has a gear change structure (+1), (1F+), and can be shifted to 4 speeds. So, the auxiliary transmission? ? (D) and forward/forward switching device 1 color + ([:'l
Similarly, it consists of 6 gears, 1, 1, and 6, and each of them is configured so that some of the gears 44 of these own devices (It) and ((:) are connected.

As shown in the same figure and FIG. Hydraulic cylinder (+
3) is configured to be operated by shift 1, and these;
3 oils)! Cylinder (I +), (+2),
(+3) ε31, it operates when pressure oil is introduced from the hydraulic pump (15) via the speed change valve (14) for traveling.

In addition, the above-mentioned speed change valve (140; 1 rotary type, incline, -to speed change 'A': lf (8) and opening) type device C1 () is 11■ combined υ-, and has 8 steps. You can set the speed.

In addition, the three oil II-cylinders (D), (+2'l,
(+3) is the operating part of 34☆ replacement valve C2 two configurations 1
- and 7, each of which is configured to generate pilot pressure when operated by a device other than 1.

Factor 177 is that the hydraulic cylinder (
13) is the low speed operation position (1,) and the high speed operation position (D)
The cylinder (13) can be operated only in two positions, and the neutral position of the switching valve of the cylinder (13) functions only during operation.

Further, the front/rear i11 switching device (C) described in +iii is manually operated by a swing-type operating lever (16), and a hydraulic valve (17) is interposed in this manual operating system. In other words,
The hydraulic valve (17) is configured to generate pilot pressure when the front/rear i(1 switching device (C)) is set to the forward operation (+7 position (F)) or the reverse operation position (]υ.

The hydraulic clutch (3) is configured to be engaged when pressure oil is supplied.
1! The pressure oil is drained (11) by the oil passage (1).

saw, the hydraulic clutch (3) is -1- transmission (A);
When either the opening combination i# (R) or the forward/reverse switching device (C) is operated, the
I.

If the operation is <xr (,1, +fG and +bν), the second F clutch (2) is disengaged and the gear shift operation is performed without operating the J. is now possible.

Finally, the oil passage (19) has three passages (19a), (Hlb), which are branched from the oil passage (19).
(19c) Each of them includes a throttle valve (2(1)), a first valve mechanism (21) that closes when the pilot pressure from the hydraulic clutch side reaches a predetermined value, and a piston valve (21) from the hydraulic clutch side. , liI' where the l-pressure is greater than the predetermined value
A second valve mechanism (22), which is connected when reaching i, is installed.
A pressure crab 1 control device (D) consisting of the pressure crab 1 control device (D) is provided, and the oil passage (23) from the pressure crab 1 control device (n) is connected to the hydraulic valve (17) and the three pressure cylinders (
II).

(+2), (l) operated by pilot pressure from each
Logic valves (24a), (24h), (24c
), (24d) is installed, and the oil passage (24) on the hydraulic flange side of the logic valve group (24) is interposed.
25) is provided with an accumulator (26).

Then, put the vehicle into the running state (1), and the transmission (
When A) is set, the logic valve group (24) is brought into communication, the hydraulic clutch (3) is maintained in the human state, and the main transmission (^) is maintained in the state where the main transmission (^), When either the auxiliary transmission (B) or the forward/reverse switching system W (C) is switched, the pilot pressure from the switching system decreases during the switching operation, causing the logic valve group (24) to switch to hydraulic pressure. Pump (15
) and at the same time cut off the pressure oil from the hydraulic clutch (3).
The hydraulic oil is flowed out into the 1-len oil passage (27) and the hydraulic clutch (3) is disengaged and operated. Next, when the switching operation is completed, the logic valve group (24) is set to the continuous 4 state again, and the hydraulic clutch (3) is engaged.

Further, the pressure control device (n) and the accumulator (26) are equipped with a hydraulic cranometer (3) as described in +iii.
) is provided for the purpose of softening the shock when the hydraulic clutch (3) is operated manually and shortening the time it takes for the hydraulic clutch (3) to reach the engaged state. I
+), the oil 11 cylinder (D) for the 1st and 2nd gears behind (12) is operated from the 1st gear side to the 2nd gear side 1! The following is an example of a case in which the value is increased by 2X.

That is, as shown in FIG. 4, changes in the pilot pressure (pz) from the hydraulic cylinder (D) during the shift operation, changes in the pressure (P25) in the oil passage (25) for the hydraulic clutch (3), An oil passage (Hl) for the speed change valve (14),
So-called Minoste J, changes in pressure (I'+8), and distortion clearing of the shift fork operated by the hydraulic cylinder (D) (Sl
The changes in the hydraulic cylinder (+) are shown in graphs.
D) starts operating, the pilot pressure (P
Il) begins to decrease, and in conjunction with this, the logic valve group (2
4) becomes cut off. And, due to this, the oil path (
25) pressure (Pzs) decreases and the hydraulic clutch (
3) is in a cut state.

Furthermore, when the hydraulic cylinder (D) is activated, the shift fork operates the gear shifting sleeve, so the shift amount Hs+, ) of the shift fork increases, and the gear shifting sleeve reaches the neutral position (n). Then, the strain M of the shift fork decreases by -4.

Next, the hydraulic cylinder (D) is in the neutral position i'tffi(n)
Since the shift fork that operates further operates the sleeve for gear shifting and synchronizes, the amount of shift I/fork distortion (S,) increases by the time required for synchronization (T), and after this, the shift of the sleeve When , the relay of shift 1 fork decreases.

In this way, when the operation for shifting is completed, the pilot pressure (PIl) increases, and in conjunction with this, the logic valve group (24) goes into the Il state.

Then, when the pressure in the oil passage (25) starts to rise, the pressure control device N(n) maintains the first valve mechanism (21) in the closed state and controls the pressure through only the throttle valve (20). In this way, when pressure oil is supplied only from the throttle valve (20), the pressure in the oil passage (25) is
0) and the accumulator (26) act (toa), and the accumulator (26) stops acting and the throttle valve (20) mainly acts (tO)
So slow speed - 1 = rise.

That is, these two time domains (t, A), (to)
The hydraulic clutch (3) is engaged during the two time ranges (t, A) and (to).
is not in a fully engaged state and is in a so-called half-clutch state, so the larger these two time ranges (t, A) and (to) become, the softer the engagement of the hydraulic clutch (3) will be. be.

Finally, when the second valve mechanism (22) is brought into communication, the pressure in the oil passage on the hydraulic pump side of the pressure control device (b) is changed to the oil passage (on the hydraulic clutch side) of the pressure control device N (n).
23) and sets the hydraulic clutch (3) to a completely connected state.

The region in which the pressure in the oil passage (25) is increased by the second valve mechanism (22) is referred to as the time region (tvz), and the region shown in the broken line graph in FIG. ) is the time range (tv+) in which the oil passage (25 ) acts on i and U7 to cause the pressure at slow speed I to be affected.

lj This [-] lid is used in the above time range (to) in order to reduce the loss of speed when changing gears when driving at heavy speeds.
The lower part should be taken for a longer time.

That is, as shown in Fig. 1, the pressure control device (I)
) is composed of 1 Zorotsk, and this block has 2 +
The throttle valve (2+) made of lV material and the spring (2]a) are used to cut the pressure to a predetermined value of 41'.
The first valve mechanism (21) and the spring (22
A second valve mechanism (22) is provided which is energized by a) and which operates when the pylon 1 pressure reaches a pressure greater than the predetermined value.

In addition, for the pressure control unit (D), a flow path (28a
) is supplied with pressure oil from the hydraulic pump (15),
In addition, it is formed in a plate shape 44'(2)1) and the flow path (211b
') to supply pressure oil to the logic valve group (24) 7. Note that both flow paths (28a) and (211h) constitute a part of the oil path (19) and the oil path (23).

The saw, the first valve mechanism (21) and the second valve mechanism (22) each have an adjustment port h for arbitrarily setting each operability 1/1.
(29), (30) KaMii board shape +K (2
B) It is set up in the state of two-way control, and people's regulation port I-(
29), by rotating (30), the first valve mechanism (21), the second valve mechanism (22) and the spring (21a)
, (22a) can be changed and set.

In history, the adjustment hole for the second valve 1 (22) - (30)
An arm (31) is attached to the outer end of the arm (31), and the sub-shift interval N (R) is attached to the end of the arm (31).
A wire whose one end is connected to the shift fork (32) of
Connect t-(33) and Mizuki to sub-transmission (R)
is set to the high speed side, the spring (
The 41 forces in 22a) are linked to -1-,4.

As mentioned above, the spring (2) of the second valve mechanism (22)
When the force A in 2a) is extended, the time range (to) is extended, as shown in FIG.

[Another example]

In addition to the present invention and Embodiment 1, for example, a throttle valve (2F+
) is configured to have a flow V, 81AI clause 7, and the throttle valve (2
(fl) and the shift fork of the auxiliary transmission (b) are linked. It may be implemented as follows.

[Brief explanation of drawings]

The drawings show an embodiment of the pressure control mechanism of the hydraulic kunitonochi according to the present invention, FIG. 1 is a diagram showing the connection between the pressure cuff J control device and the sub-transmission device (R), and FIG. A schematic diagram showing the transmission structure, Fig. 3 is a hydraulic circuit diagram for gear shifting, Fig. 4 is a graph showing pressure fluctuations in predetermined parts during gear shifting operation, and Fig. 5 is a pressure ':1 control mechanism. It is a graph showing that the half-cradle and child states of the hydraulic clutch are extended. (3)...Hydraulic clutch, (20)...
- Throttle and) valve, (21)...First valve mechanism, (22
)... Second valve mechanism, (22a)... Spring for setting the operating pressure of the second valve mechanism, (30)...
Adjustment mechanism, (32), old shift lever, (33)
...Wire, (A) ...Seikan i! Device, (II)...Sub-transmission device, (I'I)・
...Pressure control device.

Claims (1)

[Scope of Claims] [1] Traveling using a main transmission (A) configured with multiple stages, a sub-transmission (B) configured with two high and low stages, and a hydraulic clutch (3) that connects and connects the shifted power. A first valve mechanism that constitutes a transmission system and switches from a communicating state to a closed state when pilot pressure from the hydraulic clutch side reaches a predetermined value with respect to an oil passage for operating the hydraulic clutch (3). 21
), a second valve mechanism (22) that switches from a closed state to a communicating state when the pilot pressure from the hydraulic clutch side reaches a value larger than the predetermined value, and a throttle valve (20) are arranged in parallel. A pressure control device (D) is installed, and when the sub-transmission (B) is operated to the high speed side, the amount of oil per unit time supplied via the pressure control device (D) is A pressure control mechanism for a hydraulic clutch in which the auxiliary transmission (R) and the pressure control device (D) are linked so that the pressure (B) decreases compared to when the pressure is operated to the low speed side. [2] Sub-transmission device (B) and pressure control device (D)
The shift fork (32) of the auxiliary transmission (B) and the mechanism (30) that adjusts the biasing force of the spring (22a) for setting the operating pressure of the second valve mechanism (22) A pressure control mechanism for a hydraulic clutch according to claim 1, further comprising a wire (33) provided therebetween.