JPS5856930A - Sudden start preventing unit for movable working vehicle - Google Patents

Abstract

PURPOSE:To have the pressure raised again from near zero point, when the speed is changed by removing the pressure oil in the back chamber of a spring tainer spool and the pressure oil in the back chamber of an accumulator without allowing the oil to pass through a throttle hole when the transmission gear is transferred from any shift position to the neutoal. CONSTITUTION:A sudden start preventing relief valve C, provided between an oil pressure pump for a hydraulic clutch unit and a hydraulic control valve, comprises a relief valve 63, a spring refainer spool 61 which gradually changes a spring pressure of a relief valve 62 through a throttle valve 58a, and an accumulator 59 which is moved back at a speed slightly faster than the spring retainer spool 61 by the pressure oil through the same throttling. A quick return valve 58 is installed so that the pressure oil which pushes the spool 61 and the accumulator 59 may flow into a drain system without passing through the throttle hole 58a through the process of pressure drop.

Description

[Detailed Description of the Invention] The invention relates to a sudden start prevention device when the transmission is operated from a neutral position of a mobile work vehicle having a hydraulic clutch type transmission. An application has been filed regarding a relief valve for preventing sudden start, and the present invention further improves this.

Conventional sudden start prevention relief valve devices include a relief valve, a spring that connects the relief valve, and a spring that increases the reaction force of the spring over time to gradually build up the hydraulic pressure. The receiver consisted of a spool, and the spring receiver allowed pressure oil to flow into the back chamber of the spool over time through a hole. The pressure fi coming in through this hole
As the l+ pushes back the Silly Reef pulp and the pressure oil gradually rises, the hydraulic clutch device changes from a "clutch" state to a "half-clutch" state and then to a "engaged" state, preventing a sudden start.

However, re-J! When the hydraulic control valve 1 is returned to neutral, the spring returns to its original position, and the spool must quickly retreat, but the spring holder is inserted into the back chamber of the spool through the pattern hole. Since the pressure oil is flowing out, the return of the spring is slow, and when the next gear is shifted immediately, pressure oil suddenly enters the hydraulic clutch device from the high pressure position, causing a sudden start.

In order to spin this, the spring holder is provided with a quick return valve in the gap in the spool back chamber where the pressure oil returns so that it does not need to pass through the it+b hole, and the quick return pulp is
The spring holder is a combination of the back chamber of the spool and an accumulator that softens the communication hole.

The object of the present invention is as described above, and based on the structure of the embodiment shown in the attached drawings, the structure of the present invention is shown in Fig. 1 as an overall side view of a mobile work vehicle, and Fig. 2 as a power source of the mobile work vehicle. FIG. 3 is a front view of the transmission case, FIG. 4 is a side sectional view of the mission case, and FIG. 5 is a side sectional view of the reverse shaft portion.

This mobile work vehicle is a wheeled vehicle with two front wheels and two rear wheels, and the frame has a bending part (10j) at the front of the transmission case (1) between the front wheels and the rear wheels, so that it can be bent horizontally in the front and back. By rotating the steering wheel, the hydraulic cylinder is moved and the front section is deflected and steered using the power steering system.Packet 4 is placed at the front of the aircraft. , boom (J-arc boom mounting base +501
．． An engine room (@) is provided above the υ- (kerato is configured to be able to rotate up and down by the hydraulic cylinder fIIl. Rear wheel -), and an engine room (with an engine t+52J placed in the direction) is installed in the engine room. A driver's seat is provided above the driver's seat, and a forward/reverse shift lever σ4, an auxiliary shift lever (7aJ), and an inching pedal (711) are provided near the driver's seat flat.

The power transmission system will be explained with reference to FIGS. 2, 4, and 5.

A universal joint (7) is connected to the crankshaft of the engine t5a via a shock absorber (6), and the tip of the universal joint (7) is connected to the input shaft. The input shaft α is engaged with the loosely fitted gear on the forward shaft (2) by the gear QIJ inside the mission case aυ. Further, the tip of the input shaft 0L protrudes forward of the transmission case (1), drives the pump gear of the hydraulic pump (3) provided on the protrusion, and also drives the high-pressure pump 00.

The hydraulic pump (8) is a pump for supplying pressure oil to the hydraulic clutch device in the transmission case (1), and the pressure is as low as about 15. On the other hand, the high-pressure pump 00 is a high-pressure pump for moving a working machine such as a packet or a backhoe attached to the rear, and has a high pressure of about 60°C. Hydraulic oil is also contained in the low pressure pump (8) and the tension case (
1) The high-pressure pump uses a hydraulic oil tank, but the high-pressure pump also has a hydraulic oil tank from which it sucks hydraulic oil.

The loose-fit gear ■D on the forward shaft (2) is constantly driven by the gear αl on the input shaft Op, and the loose-fit gear Qυ
The loosely fitted gear ((1) on the reverse shaft αΦ is engaged at the same time.The forward/reverse hydraulic pressure control valve (2)
) By operating the spool ■ in the vertical direction, you can shift gears to neutral, forward, and reverse. In the case of neutral, the hydraulic clutch device for forward movement (8 sumo) and the hydraulic clutch device for reverse movement (8 sumo) are activated.
8) is also in a "disconnected" state. Hydraulic clutch for forward movement! If the t device (81) is in “contact”, the loose fit gear (2D
The power is transmitted to the fixed gear via the horizontal forward shaft (2), and is transmitted from the fixed gear to the fixed gear (a) above the auxiliary transmission shaft (2). Power is transmitted to. -Similarly, when going in reverse, the hydraulic clutch device for reverse (the shrine is in the "connected" state, and the power from the gear enclosure, the loosely fitted gear, and the υ side is transmitted to the reverse shaft and fixed Since the installed gear (A71) is always aligned with the fixed gear (A) on the U transmission shaft (l), power is transmitted to the sub-transmission shaft 01.

The fixed gear (4) on the sub-transmission shaft 0 meshes with the forward shaft 04, the reverse shaft α, and the gears with the same number of teeth.
The forward axis @ and the reverse axis α◆ are connected to the sub-shift axis (6
) is located on the apex of the base of an isosceles triangle with center at -. The forward shaft (6) and the reverse shaft α◆ are interlocked and interlocked by two loosely fitted gears υ (86) having the same number of teeth. With this configuration, rotation at the same speed in both forward and backward directions is transmitted to the fAU shift shaft.

In this way, while the forward and backward shifting is performed by the hydraulic clutch devices disposed half-way between the left and right sides, three-dimensional shifting is performed in the longitudinal direction on the auxiliary transmission shaft 04. That is, on the east side of the sub-transmission axis α, the hydraulic clutch devices for 2nd speed, W, 3rd speed, and 1st speed are installed from the front (h).

Free play @ gear rA in each hydraulic clutch device - υ
Diagram of hydraulic clutch system (free-fit gears (c) (c) corresponding to when any of the catches are in contact)
(A) starts rotating integrally with the sub-shift shaft (11).

Play car tv! 3 (To) (7) is constantly meshed with the fixed gear ■ @ (To) on the counter shaft C1υ, and transmits power by pulling the counter shaft α. The rotation of the counter shaft (Lυ) is transmitted from the fixed gear (g) on the drive shaft aQ to the drive shaft via the carved gear.

The rear end of the drive shaft Q. is coupled to the rear pinion shaft αη, and the front end of the drive shaft QQ is refractably transmitted from the coupling (G) to the front pinion shaft via a universal hinge.

The transmission case (1) is an open box with an integrated front wall, and the rear surface is covered with a center plate (2), and the bottom part from the 0 part of the sub-transmission shaft protrudes rearward, so it is covered with a lid (4). It's because it's covered. The front of the mission case (1) is the oil passage plate (3).
), and a hydraulic pump (3) is attached to the front of this oil road plate.
A sticker case is pasted on the forward shaft side gear shaft,
Pressure oil is sent to the reverse shaft <141.

Also, as shown in Figure 7, the strainer and its installation are also installed on the oil road plate (3).

As shown in FIG. 3, various hydraulic devices are attached to the front of the oil passage plate (3) on the front of the transmission case (1). Place the lid (4) of the second relief valve (G) on the lower side of the input shaft (AP), and the inching valve (G) on the right side of the input shaft (B).
, the sudden start prevention relief pulp (O and below it is the auxiliary transmission hydraulic control valve 03) is installed on the right side, the forward and backward movement hydraulic pressure mlJ is installed on the lower right side, and the strainer fixed body 4 is installed below it. ing. 1411 is a dipstick equipped with a pupil.

Figure 6 is a hydraulic circuit diagram of the constant transmission device, Figure 7 is a side sectional view of the forward/reverse hydraulic control valve (5), and Figure 8 is a side sectional view of the forward/reverse hydraulic control valve (5).
The figure is a side cross-sectional view of the auxiliary transmission hydraulic control valve (B), Figure 9 is a side cross-sectional view of the inching valve ■, Figure 10 is a side cross-sectional view of the sudden start prevention relief pulp (Q, and Figure il1 is a side cross-sectional view of the second relief valve. It is a side sectional view of a valve (6).

As we follow the movement of hydraulic oil and explain the hydraulic system and its functions, we can see that the lubricating oil collected at the bottom of the transmission case (1)
The oil is sucked in from the strainer through a suction oil passage (2a) formed between the center plate (2) and the rear surface of the transmission case (1). The sucked hydraulic oil passes from the oil passage in the center plate (2) through the connection oil passage (LA) in the transmission case (1) to the alignment between the front of the transmission case (1) and the oil passage plate (3). It enters the oil passage, rises, is sucked into the hydraulic pump (8), and is discharged as pressure oil.

The strainer (2) is installed in a connecting oil passage (1) fixed between the center plate (2) and the front of the strainer case (1), and is surrounded by a protected area.

When the engine is stopped, a normal strainer is immersed in the hydraulic oil, but the strainer with this configuration is above the oil level and filters the lubricating oil that is being sucked in, so it is used for cleaning purposes. This means that the hydraulic oil will not spill even if it is drained. By removing the strainer attachment body (8), the strainer TST can be taken out and cleaned together with the fitting body. (
At 54a), a plate spring is used to bring the strainer and the strainer into close contact with each other.

Pressure oil discharged by the hydraulic pump (8) reaches the auxiliary transmission hydraulic control valve (8).

The pressure oil of the P boat in Fig. 8 is fed. Fig. 8 shows a neutral state, and the P boat is connected to the through oil passage (56a), but Since the other end is closed, the pressure oil is flowing in the direction of the IJ-F valve (0) that prevents sudden start. Also, the hydraulic clutch device for forward 3 speed (the return oil from the F3 boat in the state is flowing in the small diameter part (56d) to the drain boat, similarly, the F2 boat flows from the sliding part (56e) to the drain boat, and the Fl boat flows from the notch (56d) to the drain boat (]○)0 Sub-transmission spool handle When the boat is pulled up one step, the P boat is connected to the Fl port through the notch (56b), and the pressure oil is supplied to the first port.
The continuous hydraulic clutch device is in the "engaged" state. The F2 boat uses the through oil passage (56a), and the F3 boat uses the small diameter section (56a).
6d) to the drain boat.

When the P-boat is pulled up one more step, the f
The 40F3 boat has a sliding part (connected to the iF2 boat) and the 2nd auxiliary gear, and the Fl boat has a penetrating oil passage (56&).
56c))) When pulled up further, the P boat is connected to the F3 boat through the through oil passage (56a), and the auxiliary gear is set to 3rd gear, and the Fl boat is connected to the detent groove. N to the drain boat, and the F2 boat is connected to the drain boat via a cutout (56b).

In addition, the pressure oil of the hydraulic pump (8) is supplied to the inching valve (2).
Oil is sent to the forward and backward movement valves through the .

Inching valve 0 is the inching pedal συwo (11
) This will drain the pressure oil from the hydraulic pump, causing a momentary drop in pressure. Each hydraulic clutch device is
Even if the clutch is in the "closed" state, the hydraulic clutch for forward and backward movement changes to the disconnected state by operating the inching valve 0.

The state of the inching valve shown in Fig. 9 shows a completely closed state, and all the pressure oil flows from the P boat to the A boat through the notch (57b). )
This is due to the flow. From this state, when the inching valve β7) of the inching valve 0 is pushed in using the inching pedal συ, the inclined surface (57c) communicates with the trowel port, and a part of the pressure oil flows to the lubricating oil boat. It is. (g) The boat has a second relief valve■
However, the second IJ IJ-7 valve is set to a low pressure of 2 to 3, so the hydraulic circuit is 2 to 3.
When the pressure is low, the hydraulic clutch device for rigid speed becomes a half-clutch.

By depressing the inching pedal 4 against the spring so that the slope (57g) gradually opens to the L boat, the strength of the half-clutch state can be adjusted (12). If you step on the inchingesbourg, the pressure oil in boat A will drain and the hydraulic clutch device for forward and backward movement will be completely disconnected.However, the pressure oil in the hydraulic clutch device for auxiliary transmission will Since the second relief valve (■) is held down by the second or third position, it stops in a half-clutch state.

Pressure oil passing through the inching valve (2) reaches the forward/reverse hydraulic control valve (A).

Figure 7 shows the neutral state of forward/reverse gear shifting, and the pressure oil that has reached the P boat is at the notch (53c) in the forward/reverse gear.
It flows from the boat to the lubricating oil channel. When the forward and backward spool is raised, the boat moves forward, and the pressure oil of the P boat flows from the through oil passage (53b) to the F boat and reaches the forward hydraulic clutch device body 1). On the other hand, if you lower the Sugeru for forward and backward movement, the pressure oil of the P boat will move to the left at the notch (53c).
From there to the R boat, the hydraulic clutch device for reversing is brought into contact.

When the inching valve (2) is open and the forward/reverse hydraulic control valve is in a position other than neutral, the rigid body (13) of the hydraulic control valve is in any position and the pressure oil has no escape route. - Pressure begins to rise. If the pressure increases rapidly, the piston of the hydraulic clutch device will move rapidly, causing a jerky transmission of power and a sudden start. In order to prevent this, in order to delay the rise of pressure in such cases, a sudden start prevention IJ I7-F valve (0 pressure oil is provided) is installed in the cylinder of the hydraulic clutch device and this sudden start prevention relief valve. (Although it communicates with the P boat of 0, the spring force of the spring for returning histones of the hydraulic clutch device is thicker than the spring (62) of the spool μs), so the pressure oil first enters the back chamber (63a). pushes the relief valve against the spring (62), connects the notch (1113b) and the boat, and releases the pressure oil into L.
Let them escape to the boat. At the same time, the quick return valve also moves to the left, opening the crest hole (58a) and the notch (58a).
9a) is connected. If this continues, the pressure of the pressure oil will not rise forever, so it is necessary to gradually increase the reaction force of the spring (62). (58a),
The oil passage passes through the notch (59a) of the accumulator (
14) Pressure oil enters through (59e), and the spring receiver pushes the spool to increase the spring force of the spring (62). At this time, the quick return valve (-) is pushed by the pressure oil of the P bolt and moves to the left against the spring ([51).At this time, in order to make the rise of the hydraulic pressure curve gentle, 1. The pressure oil that has entered through the MIL (58a) and the notch (59a) is also introduced into the back chamber (59c) of the accumulator Ushi, and the accumulator ←0) is moved against the spring μs) as shown in Figure 1O. The spring receiver is configured so that the spool system moves to the right as the accumulator moves to the right. By moving the spring receiver to the right by 6 cm, the spool state gradually returns, and the pressure of the hydraulic clutch device reaches the specified pressure, resulting in a negative connection state.

In this state, when the forward/reverse hydraulic pressure control valve (5) is in the neutral position, and the inching valve (2) starts to flow pressure oil to the L boat, the oil pressure of the L boat is as low as 2 to 3, so suddenly The pressure of the start prevention relief valve (P boat of Q begins to drop. Due to this drop in pressure, the relief valve's sword immediately returns to its original position, and the spring sword returns to its original length and releases. (15) If the valve steel moves to the left and the pressure oil of the P boat is removed and the oil pressure curve is lowered to near zero, the next time the gear is shifted,
Since the clutch is connected from low pressure near zero, it is difficult to start suddenly, but the quick return valve 958
) to the left with pressure oil from the P boat, and connect the accumulator's back 8 (59 (! ) and the spring holder to the spool through the crest hole (58a) and the notch (59a) of the accumulator i5g). (Since the pressure oil is led to the back chamber (61a) of 6υ, if it comes out through the crest hole (58a) when returning, the spring holder will not be able to tie and return the spool.) -.The quick return valve v3) is provided for this purpose, and the spring holder is attached to the spool (6JJ's back chamber (61
When sending pressure oil to a), push the quick return valve example to the right side against the spring (light) with the pressure oil of the P boat, and pass it through the crest hole (58a).
6Za), but enters the back room r61a.
), when the pressure oil in the P boat goes down, the spring (-) pushes the quick return valve φ8 back to the right, and the crest hole (58a) moves to the right, opening the notch. Return (1G) of part (,59a) 9 Oil goes from the spring (opening spring chamber) to the drain oil path (s9b)
The spring holder quickly escapes after passing through the spool (6 swords move to the left, and when the next gear shift is started, the IJ is blown out with low pressure to prevent a sudden start.) In this case, the sudden start prevention +7-F valve (Q is configured in two stages, upper and lower, and the relief valve steel and spring holder are installed in series with the spool (6) J and spring (62) in one P stage, and the other stage is An accumulator 9) is provided on the outer periphery of the accumulator 9), and a quick return pulp eave 8) is installed on the inner periphery of the accumulator 9).As shown for the hydraulic circuit in Fig. 6, the forward and backward hydraulic pressure control valve When in neutral, the pressure oil of the P boat flows to the lubricating oil boat, and the pressure oil is transferred to the inching valve (6) and the inclined surface (5).
7c) If the water is to be released from water, it should also be flowed into the boat (b).

In addition, the 111J variable speed hydraulic control valve) stops the pressure oil when in neutral, and the sudden start prevention relief valve (Q) lets 'Jt out and sends it to the υ boat.

Previously, the only pressure oil that reached the t/'i color boat was leakage from the sudden start prevention relief valve (Q), and the pressure oil when each hydraulic control valve was in neutral was connected to the drain (17). Therefore, during neutral gear shifting, the pressure oil in the pump boat communicates with the drain and is almost at zero, and the sudden start prevention relief pulp (Q does not spray).
Lubricating oil discharged from the boat (1) (there was no spewing out onto the land).

The lubricating oil discharge row is connected to the forward shaft Q'4, which is equipped with each hydraulic clutch device. It is opened above the reverse shaft 0Φ and the sub-transmission shaft 0, and each seal case (shaft end oil passage (38a) (4
0a) (39a) leads to each discharge port (801).The pressure oil discharged from the lubricant discharge row lubricates the friction plate portion of the hydraulic clutch device from the inside, but the lubrication is carried out for a long time in the neutral state. The drag plates become entangled and the car shell starts moving when it should have stopped. There is.

The pressure of the lubricating oil boat is set low. 1st
Figure 1 shows ■Boat's second relief valve @ or 1. Insert the valve teeth 151 through the oil passage plate (3) and the case (1), stopping at the stepped part, and equip the spool and spring (1B) with the thread (67) inside the valve case. It is fixed with the lid of the second relief valve.

When the pressure starts to rise 9 points above the set value, pressure oil enters the back chamber of the spool through the oil hole (65a), and the school moves to the left with a spring (
67) and press against the notch (66b) of the Snow Loo.
2! >E Harpke-xvJB) o Incision part (65b)
Low pressure lubricating oil flows out through K.

In this way, with this configuration, the hydraulic clutch (19) can be used even when in neutral mode. It'll 7jl A sudden start prevention relief pulp (Q is a relief pulp (
63) The spring holder that gradually changes the spring pressure of the relief valve spring (62) through the hole (58a) is the spool (υD), and the spring holder is the spool (slightly faster than the δ sword, but the same It consists of an accumulator (50) that is retracted by pressure oil through the ridge, and in the process of lowering the pressure, the spring holder is connected to the spool spool and the accumulator 150.
A quick return valve is provided so that the pressure oil released by pressing 1 flows to the drain circuit without passing through the throttle hole (58d), so when shifting from the gear shift state to neutral, the spring holder will release the pressure in the back chamber of the spool. Since the oil and the pressure oil in the back chamber of the accumulator suddenly escape without passing through the hole, the relief valve spring can be reduced to its original length and reaction force, and the pressure will be restored the next time the gear is shifted. It is possible to create a start-up and half-clutch state from a position close to zero.

[Brief explanation of the drawing]

(2ω Figure 1 is an overall side view of the mobile work vehicle, Figure 2 is a power transmission diagram of the mobile work vehicle, Figure 3 is a front view of the MiJeon case, and Figure 4 is a side sectional view of the Minyong case. , M5 is a side sectional view of the reverse shaft (141 part), Fig. 6 is a hydraulic circuit diagram of the device of the present invention, Fig. 7 is a side sectional view of the forward/reverse hydraulic control valve, and Fig. 8 is the auxiliary transmission hydraulic pressure. Fig. 9 is a side sectional view of the inching valve (2), Fig. 1θ is a side sectional view of the sudden start prevention relief pulp (0), Fig. 11 is a side sectional view of the second relief pulp (g). It is a side sectional view. (Q... sudden start prevention relief pulp (50)... accumulator country)... quick return pulp (58a)... crest hole (6 holes... spring holder is spool (62)...Relief valve spring, 1, relief valve (21)

Claims (1)

[Scope of Claims] In order to prevent a sudden start of a mobile work vehicle equipped with an m-pressure clutch type transmission device, a sudden start prevention relief pulp is provided between a hydraulic pump and a hydraulic control valve of a hydraulic clutch device. The spring holder that gradually changes the spring pressure of the relief pulp and the relief valve through the spool is connected to the spool, and the spring holder is slightly faster than the spool and is pipped by pressure oil through the throttle.
It consists of a receding accumulator, and during the pressure lowering process, the spring holder pushes the spool and accumulator 5. A quick return pulp is inserted so that the low-pressure oil flows to the drain circuit without passing through the crest. Sudden start prevention device for mobile work vehicles featuring the following features: