JPH10160015A - Installation structure of relief valve for lubricating oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the member of an oil pressure plate to serve as a double purpose, thereby lower a cost, by utilizing the oil pressure plate interposed between a transmission case and a valve case as a receiving seat for attaching a relief valve for lubricating oil. SOLUTION: A low pressure relief valve 24 is mounted on a metallic oil pressure plate 26 by which an oil passage Ra formed in the back surface of a traveling transmission case M and an oil passage Rb formed in the case mounting surface of a valve case 25 is partitioned. In the low pressure relief valve 24, the rod part 24a thereof is penetrated through a drain hole 26A formed in the oil pressure plate 26, a relief spring 27 comprising a conical coil spring is fitted around the rod part 24a projected from the drain hole 26A, and attached at a rod end part through a fitted-around spring receiving washer 28 and pulling out preventing pin 29. Then, a sealing rubber 26a is coated on both front and rear surfaces of the oil pressure plate 26. A unloaded hole 30 for penetrating the low pressure relief valve 24 is formed in the back surface of the traveling transmission case M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for mounting a relief valve for lubricating oil which regulates a maximum pressure when lubricating and supplying mission oil to various parts such as friction plates and bearings of a transmission hydraulic clutch in a transmission case. .

[0002]

2. Description of the Related Art Conventionally, in a combine or tractor, when lubricating various parts such as friction plates and bearings of a transmission hydraulic clutch in a transmission case, transmission oil in the transmission case is supplied. In supplying the transmission oil as lubricating oil, a hydraulic pump is attached to a side wall of the transmission case, an internal oil passage is formed in a case wall of the transmission case, and the transmission oil sucked through the internal oil passage by the hydraulic pump is used. The oil is supplied to the lubricating oil low-pressure relief valve mounted on the back of the transmission case, and the friction plates and bearings of each transmission hydraulic clutch are passed through the case wall of the transmission case and the internal oil passage formed on the rotating shaft of the transmission hydraulic clutch. It is configured to supply lubrication to.

Conventionally, when a low-pressure relief valve for regulating the maximum pressure of lubricating oil is mounted on a case wall of a transmission case, as shown in FIG.
2. Low pressure relief valve 24 and relief spring 27
The valve unit V integrally mounted with the valve case 2 is fitted into a hole formed in a case wall of the transmission case M, and an oil passage Ra and a valve case 2 formed on an outer surface of the case of the transmission case M are inserted.
The relief bush 31 is attached to the case mounting surface 5 through a hydraulic plate 26 that separates the Rb oil passage from the case mounting surface.

[0004]

According to the above-mentioned conventional structure, the case wall of the transmission case needs to be formed with a stepped hole that requires high precision for fitting the relief bush, and the use of the relief bush increases the cost. And there was room for improvement. SUMMARY OF THE INVENTION An object of the present invention is to simplify the mounting structure of a relief valve for lubricating oil and reduce costs.

[0005]

According to a first aspect of the present invention, transmission oil is applied to a case wall and a rotating shaft of a transmission case to a friction plate and a bearing of a transmission hydraulic clutch in a transmission case. A relief valve that regulates the maximum pressure of the lubricating oil is provided between the transmission case and the valve case attached to the outer surface of the transmission case. A mounting structure for a relief valve for lubricating oil that drains into the case, and is opened and closed by a relief valve on a hydraulic plate that separates an oil path formed on the outer surface of the transmission case from an oil path formed on the case mounting surface of the valve case. A drain hole is formed, and the drain hole is closed via a relief valve biased by a relief spring. A. [Operation] According to this configuration, the hydraulic plate interposed between the transmission case and the valve case can be used as a seat for mounting a relief valve for lubricating oil. [Effect] According to the invention according to claim 1, the hydraulic plate interposed between the transmission case and the valve case can be used as a seat for mounting a relief valve for lubricating oil. The cost can be reduced by the dual use, and the hole for inserting the relief valve formed in the case wall of the transmission case can be formed by a fool hole processing which does not require precision.

According to the second aspect of the present invention, the relief valve is inserted into the drain hole of the hydraulic plate by inserting the rod portion of the relief valve, and the relief spring is externally fitted to the rod portion protruding from the hydraulic plate in a state where the relief spring cannot be removed. [Operation] According to this configuration, the operation is performed in the same manner as the first aspect of the invention, and the reaction force of the relief spring 27 is received by the main body of the hydraulic plate 26 as shown in FIG. Then, as in the case where the relief valve 24 is pressed against the hydraulic plate 26 by the relief spring 27 so as to be urged,
Of the hydraulic plate 26 due to the repulsive force of the oil. [Effect] According to the second aspect of the present invention, the above-described effect of the first aspect of the present invention can be obtained, and also the bending deformation of the hydraulic plate due to the repulsive force of the relief spring can be suppressed.

According to a third aspect of the present invention, the relief spring receiving seat is integrally formed by swelling around the drain hole of the hydraulic plate. [Operation] According to this configuration, the operation is the same as that of the first aspect, and the eccentric attachment of the relief spring 27 to the drain hole 26A is suppressed as shown in FIG. [Effect] According to the third aspect of the present invention, the above-described effects of the first aspect of the invention are provided, and the mounting of the relief spring due to eccentricity is suppressed, so that a good spring action is exhibited.

[0008]

FIG. 1 shows the inside of a traveling transmission case M of a combine, wherein 1 is an engine input pulley 1;
an input shaft 2 having a. a, a three-speed sub-transmission gear slidably mounted on the input shaft, 3 a sub-transmission passive shaft, and a low-speed gear 4 that can mesh with the sub-transmission gear 2; A high-speed gear 5, a high-speed gear 6, and an output gear 7 to the main transmission are provided. Reference numeral 8 denotes a main transmission that is capable of shifting between three forward speeds and reverse speed. 9 is a hydraulic clutch for the first forward speed in the main transmission, 10 is a hydraulic clutch for the second forward speed, and 11 is a hydraulic clutch for the third forward speed. Reference numeral 12 denotes a reverse hydraulic clutch, and an input gear 10a of the hydraulic clutch 10 for the second forward speed is always meshed with the low speed gear 4 of the passive shaft 3 for auxiliary transmission. Hydraulic clutch 9 for first forward speed and hydraulic clutch 1 for third forward speed
The output gear 13 of the speed change shaft equipped with 1 is always in mesh with the input gear 14a of the side clutch 14. 15 is a wet disc brake, and 16 is an axle.

FIG. 2 shows the hydraulic clutches 9, 1 for shifting.
FIG. 2 shows a hydraulic circuit for hydraulic pumps 0, 11, and 12, and a hydraulic pump 1;
Alternatively, pressure oil is supplied from 9 via a rotary valve 20 to the shift hydraulic clutches 9, 10, 11, and 12. 21 is the transmission hydraulic clutch 9, 10, 11, 1
2, a reaping clutch piston for turning on and off the reaping clutch, 23 a high-pressure relief valve for regulating the maximum pressure of the shifting hydraulic clutches 9, 10, 11 and 12, and 24 a shifting hydraulic pressure. R is a low-pressure relief valve that regulates the maximum pressure of lubricating oil on the clutches 9, 10, 11, and 12, and R is a lubricating oil supply oil passage.

FIG. 3 shows a structure in which the high-pressure relief valve 23 and the low-pressure relief valve 24 are mounted on the back of a traveling transmission case M. The high-pressure relief valve 23 and the low-pressure relief valve 24 The hydraulic pump (not shown) mounted on the side wall of the traveling transmission case M is provided for the high-pressure relief valve 23 and the low-pressure relief valve 24 of the valve case 25. After the transmission oil in the traveling mission case M is supplied to the high-pressure relief valve 23 and the low-pressure relief valve 24 via internal oil passages formed in the side wall and the rear wall of the traveling mission case M, The internal oil passage formed on the rear wall and side wall of the case M and the main transmission That is the lubrication to the rotating shaft via the internal oil passage forming such friction plates and bearings of each shifting hydraulic clutches.

As shown in FIG. 4, the low-pressure relief valve 24 is made of a metal that separates an oil passage Ra formed on the back surface of the traveling transmission case M and an oil passage Rb formed on the case mounting surface of the valve case 25. It is mounted on a hydraulic plate 26. The low-pressure relief valve 24 has a valve rod portion 24 a having a drain hole 26 formed in a hydraulic plate 26.
A, a relief spring 27 composed of a conical coil spring is externally fitted to a rod portion 24a projecting from the drain hole 26A, and attached to the rod end via an externally fitted spring receiving washer 28 and a retaining pin 29. ing.
The hydraulic plate 26 has rubber 26 for sealing on both sides.
a, 26a are coated. On the rear surface of the traveling transmission case M, a fool hole 30 for inserting the low-pressure relief valve 24 is formed.
4, the mission oil is drained.

As shown in FIG. 5, the hydraulic plate 26
Are formed with communication holes a for communicating the respective oil passages formed on the rear surface of the traveling transmission case M and the respective oil passages formed on the case mounting surface of the valve case 25.

Therefore, according to the above structure, after the transmission oil is sucked through the internal oil passage formed on the side wall of the traveling transmission case M via the hydraulic pump mounted on the side wall of the traveling transmission case M, M supplies pressure oil to the lubricating oil passage of the valve case via the internal oil passage formed on the side wall and the rear wall of the M, and thereafter, the internal oil passage formed on the rear wall and the side wall of the traveling transmission case M and the main transmission. The lubricating oil is supplied to the friction plates and bearings of the respective shift hydraulic clutches through the internal oil passage formed on the rotating shaft in the above, and the lubricating oil is drained into the traveling transmission case M by the operation of the low-pressure relief valve 24. Become.

[Another Embodiment] As shown in FIG. 6, the periphery of a drain hole 26A of a hydraulic plate 26 is formed by squeezing to the inside of the traveling transmission case M by drawing, and a receiving seat 31 of a relief spring 27 is integrally formed. Formed. With this configuration, the eccentric attachment of the relief spring 27 to the drain hole 26A is suppressed, and the spring action of the relief spring 27 is sufficiently exhibited. (Note that components having the same functions as those of the above-described embodiment are denoted by the same reference numerals and symbols as those of the embodiment.)

Further, in the above embodiment, a conical coil spring is exemplified as the relief spring 27, but a cylindrical coil spring may be used.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a transmission structure in a transmission case.

FIG. 2 is a hydraulic circuit diagram

FIG. 3 is a side view of a transmission case.

FIG. 4 is a cross-sectional plan view showing a mounting structure of a relief valve.

FIG. 5 is an exploded perspective view of a relief valve.

FIG. 6 is a cross-sectional plan view showing a deformation of the hydraulic plate.

FIG. 7 is a comparative example showing a mounting structure of a relief valve.

FIG. 8 is a conventional cross-sectional plan view.

[Explanation of symbols]

 9-12 Shift hydraulic clutch 24 Relief valve 24a Rod part 25 Valve case 26 Hydraulic plate 26A Drain hole 27 Relief spring 31 Receipt M Transmission case Ra Transmission case side oil passage Rb Valve case side oil passage

Claims (3)

[Claims] The transmission oil is lubricated to various parts such as a friction plate and a bearing of a shifting hydraulic clutch in a transmission case through an internal oil passage formed in a case wall and a rotating shaft of the transmission case. A relief valve for lubricating oil is provided between the transmission case and a valve case mounted on the outer surface of the transmission case to provide a relief valve that regulates the maximum pressure of the lubricating oil, and drains part of the lubrication oil into the transmission case. So,
A drain hole that is opened and closed by a relief valve is formed in a hydraulic plate that separates an oil passage formed on the outer surface of the transmission case and an oil passage formed on the case mounting surface of the valve case, and the drain hole is urged by a relief spring. Mounting structure of a relief valve for lubricating oil that is closed via a relief valve. 2. The relief for lubricating oil according to claim 1, wherein the rod portion of the relief valve is inserted into the drain hole of the hydraulic plate, and the relief spring is fitted to the rod portion protruding from the hydraulic plate in a stopped state. Valve mounting structure. 3. The relief spring receiving seat is integrally formed by swelling around the drain hole of the hydraulic plate.
The mounting structure of the relief valve for lubricating oil described in 1.