JPS5981231A - Inching controlling apparatus - Google Patents

Abstract

PURPOSE:To soften the variation of the clutch pressure on stepping-in a pedal by varying the output pressure of an inching valve according to the displacement of the valve, even if the output pressure supplied from a pressure adjusting valve is low, by means of a inching control apparatus for the transmission gear of an industrial car. CONSTITUTION:The upper-half figure of an inching valve 20 shows the state in which a pedal is not stepped-in. The output pressure of a pressure adjusting valve 10 is input into ports (a) and (f) through a line 31, and transmitted into an oil chamber 25 from the port (a) through ports (b) and (i), and then pushes a spool 21 leftward together with a spring 24. On the other hand, an input pressure also acts into an oil chamber 27 from the port (f) through a center oil chamber 26 and a hole 28, and pushes the spool 21 rightward together with a spring 28. Said input pressure is introduced into a selector valve 40 as it is from an output port (g). In this case, input is switched between C/L1 and C/L2 for each clutch according to the position of the valve 40 for each neutral point, advance stage F, and retreat stage R, and the pressure gently adjusted by a modulator valve 60 through a change valve 50 is applied to each clutch.

Description

[Detailed Description of the Invention] Is the X invention an inching system for dual-purpose transmissions? Regarding MJ equipment.

There are various methods for controlling the inching operation of conventional industrial dual-purpose transmissions, especially transmissions equipped with torque converters and oil-operated friction engagement elements (generally clutches). Among them, for example, as disclosed in Japanese Patent Publication No. 52-34088, the inching valve is connected as shown in Fig. 1 from source → mFF-tp → selector pulp → change pulp → modulator pulp → clutch g
There is a method of performing inching control against clutch sweat by using an inching valve in a hydraulic system and controlling the adjustment pressure of a modulator pulp by an inching valve according to the stroke of the brake pedal depression. This method does not affect the modulator pulp output pressure while the pedal depression is small, and when the pedal depression exceeds a predetermined pedal depression, the control pressure that decreases as the pedal depression increases is used as the modulator valve output EF. It is something that makes it work.

The modulator pulp clutch is designed to engage smoothly and smoothly, but with this method, as shown in the graph of Figure 1, even if the displacement of the indenter valve reaches its maximum range, the residual pressure occurs. This remaining FF is 1, because it causes clutch drag when the inching valve is fully stroked (when the pedal is fully depressed). As a result, the life of the engine will be shortened, and the residual pressure will increase. When you release the pedal a little, you may experience a start-up shock.1. There is also.

In other types of devices, for example, as shown in FIG. 2, clutch pressure (inch cylinder control pressure), oil temperature, engine rotation v! There is a drawback that the clutch engagement start point (and release point) cannot be accurately determined depending on the valve displacement.

The present invention does not solve the drawbacks of the conventional method as described above.
To obtain an inching control device that generates clutch pressure that accurately corresponds to the operating stroke of the inching valve and provides an inching control pressure that is not affected by the engine speed, and furthermore, In addition, it is possible to obtain inching control equipment that does not cause residual "
It is an object of the present invention to provide an inching control device that does not cause force fluctuations and does not cause rapid rrEF '7VW movement even temporarily over the entire inching valve operating range.・
That is, the engine control device of the present invention is capable of controlling the oil g: source, the amount of friction f! Xf# - Coupling device h, counterbalance In the oil path connecting the frictional engagement device to the hydraulic pressure source, input the output pressure of the 0-pressure valve with a weight of 1n in sequence from the hydraulic source side, and output the inching control pressure. Input the control pressure of the input valve and the input valve to selectively engage the frictional engagement device.
The inching pulp is made up of a selector pulp to be released, and the inching pulp outputs the output pressure of the pressure regulating valve (8) as it is when the inching pedal is not depressed. outputs a control pressure that decreases in response to an increase in T.

' □The inching valve is pressed (4) through the (first) spring by the inching rod that is interlocked with the pedal, and is biased by the (second) spring in opposition to the (first) spring. The pressure of the pressure regulating valve is controlled by activating the inching pressure spool, which has a spring back pressure and a plurality of (first and second) pressure receiving parts that work against each other, thereby controlling the inching rod. By elastically contracting and displacing the (first) sub II ring, the input pressure to one (pile 2) pressure receiving part of the pressure receiving part opposing the (first) spring is first cut off, and then the input pressure to the one (pile 2) pressure receiving part opposing the (first) spring is cut off. 2) A predetermined control pressure is output by bringing the pressure receiving part into a discharged pressure state and applying the control pressure by the inching spool to the other (first) pressure receiving part. That is, the inch diameter valve has a land which is biased in opposite directions by springs (first and second) when the cylinder is rotated inwards, and a land which controls the input pressure. 1. An inching spool equipped with a pressure receiving part (i-th, tIgg) that acts in the same direction as the second spring, and an FF inside the cylinder.
'E n Ml When a pressing force is applied to the inching spool through the (first) spring, the land operates in conjunction with the pedal and controls the input pressure to the (second) pressure receiving part. It has an inching rod, a (first) 71 chamber that accommodates the (first) pressure receiving part and receives the pressure adjustment of the inching spool, and a T (second) oil chamber that acts on the (second) pressure receiving part. , the inching rod exerts an input pressure P on the (second) oil chamber until it reaches a predetermined displacement, and when it reaches the predetermined displacement, it cuts off the input pressure and then releases the output in the (second) oil chamber.<
, ty=The inching spool has each boat arranged in the cylinder so as to output a regulated pressure that gradually decreases in accordance with the displacement of the inching rod (input pressure I is low) in the region after the predetermined pressure point [ 7 composition, zajru.

Based on these various configurations, according to the invention, the clutch pressure (therefore 7
The change in the clutch torque) is constant regardless of the engine speed, and the inching state (that is, the half-clutch state)
make the gradient of change gradual.

Furthermore, the residual pressure of the inching valve's output pressure (therefore, the clutch pressure) is reduced to zero when the inching valve is fully stroked in response to the full depression of the pedal, thereby reducing clutch drag and increasing clutch durability. Does the loss of residual pressure cause a start shock when the pedal is released? To prevent.

Furthermore, as an aspect of the present invention, these hydraulic circuits are housed as a unit in one block, and a compact and reliable inching control device fN:rJ[: is provided.

The present invention will be explained below based on Examples.

No. 41 shows a flowchart of an embodiment of the inching control device of the present invention. That is, hydraulic power source → adjustment valve → inching valve → selector pulp → each clutch C/LX, C/L
In the oil passage configured as 2, the oil passage that branches between the select valve and each latch becomes the change valve.
It is connected to the modulator pulp.

FIG. 5 shows a detailed hydraulic circuit of this embodiment. The oil pump 1 as a hydraulic pressure source is rotated by an engine output shaft (not shown). The discharge port of the pump 1 is connected to the input port of the pressure regulating valve 10. -) Connected to 1r via line 30 ((7) ff, ?n branched and connected to torque converter T/C via orifice 4 Fn, , F, etc. are supplied as lubricating oil to the lubricating part of the clutch. Wow, ru.

It is connected to ports a and f of the inching valve 20 via the output boat aG line 81 of the boat 10, and the selector pulp 40 is connected via the output port 7 to the GJ line 82.
Connect to input port c of . Each output port b of the selector hak240, dGj4 clutches C/Ll, C/
It is connected to L2 through a line 83.88'', and is branched to each output port ha, b of the change pulp 50.
Connect to.

The output port c of the change valve 50 is connected to the input ports a and f of the modulator pulp 60 through the entire line 84.
Ru. Each boat of modulator pulp 60 1. The drained oil from ~e returns to the oil pan 2 via line 85. On the other hand, the drained oil from the discharge boats a and e of the selector valve 40 returns to the oil pan 2 via a line 85'.

On the other hand, from the boat c to the orifice 5
．． It also goes to oil pan 2 via line 88 (8), and on the other hand, it goes from boat C' to oil pan 2 via filter 8.
Return to

The pressure regulating valve 10G itself may be a known one, and the spool 1
The land 12 between the oil chamber 16 and the boat Q+Q'' is balanced by the biasing force of the 1Gr sub 11 ring 15 and the input pressure, that is, the pressing force due to pressure regulation, which acts on the land 12.18914 in opposition to this T1. The pressure is adjusted by changing the opening degree of the 17G7 spool 11.
: It's Meno Stoppa Hibinino.

The selector pulp 40 is of a known type and selectively connects or closes the input port c to the output ports l) and d by switching a spool 41 having two lands. Forward F, backward R of change valve 50 selector pulp 40
Depending on the switching, any one of the outputs is selectively supplied to the modulator pulp 60.

The modulator valve 60 may be of a known type, and the detailed explanation will be omitted, but from the left, it has a land 61a and a line cylinder 68X between it and the piston 62! F - Spools 61 interposed and pressed against each other. Orifice 64 & Spring 65
The second piston 64 (boat e) is biased to the left by
, f) is used to control the output pressure of the ininda valve 20, that is, each clutch C/Ll,
The degree of change in clutch pressure applied to C/L2 is determined.

One of the clutches C/LX and C/L2 is engaged and the other is released depending on the F and N positions of the selector pulp, respectively. In the N position, the inching valve 20 has a spool that the inching rod presses through a spring, and the spool has a spring back pressure in the opposite direction, and the control pressure and input pressure of the spool are Separate spool types are used that act against each other on the piston parts.

: The inching valve 20 is located inside the cylinder (first
．． 2nd) Lands 21 & 2 are biased in opposing directions by springs 28 and 24 and are arranged to control the input pressure.
1b and receives acting force in the same direction as the (pile 1, second) spring 28, 24, respectively;
(@1. 2nd) U [Fg ((21
a, 21 c C husband k (1st) oil chamber 27, (2nd
) and an oil chamber 25 having a working surface). Similarly, the inching spool 21 is arranged coaxially within the cylinder and is connected to the first splinter 28Tr via the first splinter 28Tr.
The in-equal rod 22 that presses the pedal (not shown,
The inching pedal (or brake pedal) is operated in the direction of arrow A in conjunction with the brake pedal (pedal on the rod). The indenter U joint 22 has lands 22a and 22b.
The input pressure to the (second) oil chamber housing C is ba, b,
1, when it is not in operation (the upper half of No. 5 Ii 2120), and when it is in operation (the lower half of Fig. 6), it first closes the boat a, and then when it is further stroked, it opens the discharge boat C, and ( 2nd) Cut off/release the input pressure to mW. In order to ensure this kind of operation, the length between boat a and boat C and the shortest length of the inner edge part) LX and land 221
and! (11) The relationship with L2 is LX>L2, and preferably L
If l-L2=fi, 1 is 0.5 to 1. Set it to On.

Spool No. 21 has a pusher 8 that communicates the (first) oil chamber with the central oil chamber (control oil chamber) 26. The first oil chamber applies control pressure to the right in FIG. Small diameter @21o
The central oil chamber 26 is formed and the land 21& is restricted to a direction in which the capo-hf is closed when the capo-hf is moved to the right (when the pedal is depressed). 21st land 2 of spool 21 ],
b closes the discharge port hill when it is inactive and opens when it is active. At the left end of the spool 21, a 11111 portion 21d which also serves as a seat for the first spring 28 is formed. There is.
,.

The (second) oil chamber boat 1 is always in communication with the (second) oil chamber 25.

The discharge lines d and e always communicate the housing chamber of the first spring 28 with the discharge line 87. Note that the working surface of the first piston is (12) smaller than the working surface of the second piston.

The inching rod 22 forms a passage between bo)a and bho by means of the small diameter portion 2zd between both lands. The state when the pedal is not depressed is shown in the upper half of FIG.
The output of O is inputted to boats a and f via the output control line 81, and from boat a it reaches the second oil chamber via boats b and i.
Push the spool 21 to the left together with the second spring 24. nk: On the other hand, from the bow hf to the central oil chamber 26. Input pressure also acts on the first oil chamber through the hole 28, and the first spring 28
At the same time, the spool 21 is pushed to the right.

Since the leftward pressing force is large, the state of the upper half of FIG. 520 is maintained, the discharge boat h is closed, and the output port
From g, the input pressure is directly introduced as line pressure to the select pulp 40 via the line 82.

In this case, depending on the neutral N (state ? in Figure 6), forward F, and reverse R positions of the select pulp 40, each clutch is switched off, input to C/Ll, and input to C/Lg (7). ,
Gently adjusted pressure is applied to each clutch via the change valve 50 to the modulator valve 60.

When you start stepping on the pedal, the inch fern rod 22Gr
It begins to move in the direction of arrow A and ends up closing input boat A. When the pedal is further depressed, the discharge boat c opens and the pressure in the second oil chamber 25 is released. The pressure in the second oil chamber 25 corresponds to the difference in the resiliency between the first spring 28 and the second spring 24.
,=, Since it is only an EF force, it moves gently to the right in response to the opening of the discharge boat c, and assumes a position intermediate between the position shown in the lower half of Figure 5, 20. At this time, the discharge boat h begins to open and the input boat f begins to close, so that the oil pressure in the central oil chamber 26 drops from the initial pressure in steps.

At that time, the pressure in the first oil chamber is equal to the oil field in the central oil chamber 26, so the rightward pressing force of the first spring due to the right side of the spool 21G and the right shaft 22 and the first piston portion 2l,
The resultant force of the rightward pressing force from the first oil chamber acting on a,
It assumes a position in balance with the force of the second splinter 24.

In the graph of Fig. 8, p - q
The clutch clutch represented by In, which is represented as a curved path from −r to 6, is traced according to the displacement of the inching valve. In this case, at point fr, the pressure moves by V, and there is no such phenomenon as shown, for example, by the two-dot # line.

When the Sarani pedal is depressed, the pressing force of the first spring 28 increases, so the pressure in the first oil chamber 27 gradually decreases, and the spool 21 gradually moves to the right and finally reaches the position where the input boat f is closed (the first (lower half of Figure 5). At this time, the discharge boat h is opened at the same time, and as a result, the output EF to the line 82 is
becomes zero. At almost the same time, the tip of the inching rod 2
1o comes into contact with the inchingespool 21 and is further depressed.
When this occurs, the inching spool 21 is moved to the right without going through the G gas pressure 28 to maintain the output pressure at 0. (
Point 8) on the graph in Figure 8).

As the pedal is gradually returned from the fully depressed position, the above steps pass in the opposite direction, and when the pedal returns to the predetermined position, it reaches the step at point r-q, and the output pressure of the pressure regulating valve IO remains as it is (15). Output Fn is on line 82. When the pedal is further released, the inching rod 22 is completely restored to its original position, and the output pressures are equal during this time.

The present invention is based on the above-described configuration, and as shown in FIG. 8, the output pressure (control pressure) of the inching valve during inching operation is controlled by the spool 21, which is directly controlled by 1 HP when the pedal is depressed, and the inching rod. The output pressure is applied to the spool 21 via the first spring and moves in accordance with the resultant force of the control pressure acting on the spool 21 under the action of the opposing spring and the output pressure changes according to the displacement of the valve. Therefore, as shown by the dotted line in Figure 8, even when the engine speed is low and the output pressure from the pressure regulating valve is low, the change in the output pressure of the 1-inch inductor valve is due to the displacement of the valve. It is possible to make a constant change in response to the change in the amount of oil from the hydraulic source.The opening movement of the axle torque (clutch pressure) when the pedal is depressed is relaxed due to changes in the amount of oil from the hydraulic source.

In response to the displacement of the inching rod 22, the input J to the second oil chamber is first cut off, and then the pressure is discharged from the second oil chamber 25 (16) C, so that the inching valve 21 is gently adjusted (Fig. 5, bottom). (state shown in the first half).
At point r in FIG. 8, pressure fluctuations as shown by the two-point chain do not occur. Therefore, a start shock caused when the gear is changed simultaneously with the inching pedal return is prevented. Further, in the pressure regulating valve 1o, the spool is also prevented from suddenly operating due to the above-mentioned pressure fluctuation, and damage to the contact portion with the stopper, the holding portion of the spring, etc. is also prevented.

As is clear from the above explanation, when the pedal is fully depressed, the output of the inching valve becomes zero and no residual pressure is generated.

In the above embodiment, a pair of springs (1st and 2nd) and a pair of pressure receiving parts (1st and 2nd) are placed at one position relative to the spool 21.
However, each of these elements can be configured as a combination of two or more elements.

Next, FIG. 6 shows a sectional view of an apparatus incorporating the above-described embodiment as one block. In this way, the device of the present invention can be constructed as a compact unit, easy to assemble into a vehicle, and easy to maintain.

[Brief explanation of the drawing]

Figures 1m and 2 are graphs showing the relationship between valve position and clutch pressure according to the conventional method, Figure 8 is a graph showing the relationship between valve position and clutch pressure according to an embodiment of the present invention, and Figure 4 is a graph showing the relationship between valve position and clutch pressure according to an embodiment of the present invention.
The figure is a 70-chart of an embodiment of the present invention, Figure 5 is a hydraulic circuit diagram showing an embodiment of the device of the present invention, and Figure 6 is an assembly block that unitizes the embodiment shown in Figure 5. A cross-sectional view of each is shown. 10... Adjustment EF120... Inching valve, 21
...Inchingesbourg, 22...Inchingrod, 28.24...1st. No. ji! spring, 25
．． 26.27...Second. Center, 1st oil chamber, 40...
・Selector valve, 50...-Change valve, 60・
...Modulator valve, C/LX, 2...Clutch, T/C...Torque converter (19) Fig. 1 Fig. 2 m'ゝ/L, "7" variable fL
／＼゛ノL7bu“Benjinto position valve mai standing

Claims (1)

[Claims] A hydraulic power source, a plurality of frictional engagement devices, and the hydraulic power source! ! Inching control is performed by inputting the output pressure of the pressure regulating valves sequentially from the hydraulic source side into the oil path connecting the frictional engagement device and the pressure regulating valves!
The inching valve is composed of an inching valve that outputs an output, and a selector that inputs the control pressure of the inching valve to selectively engage and release the frictional engagement device. The output pressure of the pressure regulating valve is controlled by operating an inchingesbourg equipped with a plurality of pressure receiving parts that act against each other to suppress the pressure through a spring and to act against the spring back pressure FnF and the like. , the indenter rod retracts the strip cylinder 2 from a state where the control pressure boat, which is in communication with one of the pressure receiving parts facing the spring, and the input boat, into which the output pressure from the pressure regulating valve is introduced, are in communication. When the displacement becomes n, the communication between the control boat and the input boat is cut off, and then the control pressure boat is communicated with the discharge boat, and the control pressure by the inchinges spool is applied to one of the 9FFa. Inching control device.