JPH0351520A - Increased pressure transmission device - Google Patents

Abstract

PURPOSE:To reduce the dimension and weight of a hydraulic pump and facilitate air venting-off work by installing a booster which outputs a hydraulic pressure which is amplified according to the difference of the sectional surface area of a piston onto a hydraulic actuator and installing a check valve onto the booster. CONSTITUTION:A hydraulic actuator 77 is equipped with a booster 83 which receives the pump pressure of a hydraulic pump 101 and outputs a hydraulic pressure which is amplified by the difference of the sectional surface area of a piston. A check valve 115 is installed onto the booster 83. When air venting-off is carried out for the hydraulic actuator 77 and the booster 83, the check valve 115 is opened, and the pressurized liquid supplied form the hydraulic pump 101 can be supplied into the hydraulic actuator 77. Therefore, the small-sized and lightweight hydraulic pump can be obtained, and the air venting work can be facilitated.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a pressure increase device for a hydraulic actuator.

(Prior Art) As a conventional power transmission device using a hydraulic actuator, there is one described, for example, in Japanese Patent Application Laid-open No. 194147/1983.

This is a differential limiting device with a locking clutch that can be operated by a hydraulic actuator with a piston-cylinder structure.
As shown in FIG. 5, the differential case 201 is
03.205, the differential case 201 is rotatably supported by the differential carrier 207.
The differential case 201 is rotatably driven from a drive pinion 209 rotatably supported by the differential case 201 via a ring gear 211 fixed to the differential case 201.

Also, inside the differential case 201 is the iJ's pinion gear 2.
13 is rotatably supported by the pinion gear 1/foot 215, and a pair of left and right side gears 217 are meshed with the pinion gear 213, and a drive for rotationally driving the right wheel on both side gears \7217, respectively. shaft 21
8 are engaged by spline.

The differential gear mechanism is roughly constructed as described above, and when the differential case 201 is rotationally driven as described above, the pinion gear 213 revolves through the pinion shaft l-215, and When the vehicle is traveling straight, both side gears 217 are driven at a constant angular speed, and when the vehicle is turning, the pinion gears 213 are driven at a constant angular speed while giving a relative rotational speed difference between the white 'Pt: l no-c nox 201 and both side gears 217 as they revolve. In the interior of the differential case 201, the differential case 2 is driven with a required angular velocity difference.
01 and both side gears 217, a plurality of clutch plates arranged alternately engage with each other in the rotational direction, and each constitutes a restraint clutch 219. Each restraining clutch 219
is connected or disconnected by the operation of a hydraulic actuator 225 provided in the differential carrier 207 and consisting of a piston 221 and a cylinder 223. Pressure hydraulic oil can be supplied to the cylinder 223 via an oil passage 227.

The differential limiting device is roughly configured as described above. For example, when one wheel starts idling, when pressure hydraulic oil is supplied to both hydraulic actuators 225 via the oil passage 227,
The piston 221 moves and the restraint-3 single-batch clutch 219 is connected, the differential rotation between the differential case 201 and the left and right side gears 217 is limited to c%, and a large driving force is transmitted.

(Problem to be Solved by the Invention) However, in such a conventional device, pressure oil is directly supplied from the hydraulic pump to the hydraulic actuator 225.
Since the hydraulic pump was used to move the piston 221 by sending it to the piston 221, the hydraulic pump had to be larger and heavier in order to obtain high working pressure, and the pulsation of the hydraulic pump affected the connecting force of the restraint clutch 219, making it difficult to stabilize the hydraulic pump. There is a possibility that performance may not be obtained.

On the other hand, in order to obtain a high operating pressure with a small pump pressure, the pressure from the hydraulic pump may be increased by a booster and then supplied to the cylinder.

However, with this configuration, there is a problem in that the air must be removed from the cylinder and the booster separately, making the air removal operation extremely difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pressure increase device that can obtain a high operating pressure with a small pump pressure and also allows easy air bleeding work.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a hydraulic actuator with hydraulic pressure that is amplified by the difference in the cross-sectional area of the piston in response to the pump pressure of the hydraulic pump. A pressure booster is provided for outputting the pressure, and a check valve is provided in the pressure booster, and when the hydraulic actuator and the pressure booster are vented, pressure fluid from the hydraulic pump is supplied to the hydraulic actuator. It was designed with features that made it possible.

(Operation) According to the above structure, the pump pressure of the hydraulic pump is amplified by the pressure booster, so a high operating pressure can be obtained with a small pump pressure.

Additionally, when bleeding air from the hydraulic actuator and pressure booster, the check valve opens to allow pressure fluid from the hydraulic pump to be delivered to the hydraulic actuator, making air bleeding easy. .

(Example) Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a structural diagram of a power transmission device according to an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of a differential device, Fig. 3 is a longitudinal sectional view of a booster, and Fig. 4 is a diagram of this embodiment. 1 is a skeleton mechanism diagram showing power transmission in a vehicle using a vehicle.

First, the power transmission of this vehicle will be explained with reference to FIG.

The driving force of the engine 1 is changed in speed by a transmission 3 and transmitted to a transfer 5. The transfer 5 transmits the transmitted driving force to the left and right front wheels 9 via the front axle 7 on the one hand, and to the propeller shaft 13 via the direction conversion gear set 11 on the other hand.
3 to rear differential 15 which is the power transmission device of this embodiment.
The signal is transmitted to the rear wheel differential device, and furthermore,
The power is transmitted from the rear differential 15 to one left and right rear wheel via the rear axle 17.

Next, in Figures 2 and 4, J;Riri17>? No.15
The configuration of is explained.

In the differential case 21, the left and right support bosses 23 are bearings 25.
The ring gear 31 is rotatably supported on the differential case l/rear 27 via the flange 29 of the differential case 21.
is fixed to bolt 1 at 33. Differential carrier A727
As shown in FIG. 2, a drive pinion shaft 35 connected to the propeller shaft 13 side is rotatably supported, and a drive pinion gear X737 meshed with the ring gear 31 is attached to the rear end of the drive pinion shaft 35. is formed in the body. In this way, the differential case 21 is rotationally driven by the driving force from the engine 1.

Inside the differential case 21, a pair of binion gears 39 are arranged facing each other. The back surface of the pinion gear 39 is in spherical contact with the inner surface of the differential case 21 via a spherical washer 41, and a certain degree of tilting is allowed around the pinion shaft 43 that is loosely fitted therein. I15, the differential case 21 is divided into left and right case parts u21a and 2 lb, which are butted together and connected with a connecting bolt 21C.

Push sleeves 45 are slidably fitted into the left and right support bosses 23 of the differential case 21, and both sleeves 45
Left and right drive shafts 47 are slidably inserted through the. Side gears 49 are spline-engaged with each inner end of the drive shaft 47, and both side gears 49 are opposed to each other and meshed with the pinion gear 39.

The four side gears and the drive shaft 47 are prevented from relative sliding by a circlip 51 interposed in the engaging portion.

At the opposing part of the side gear 49, the pinion shaft 4 is provided.
A thrust block 53, which is formed into an annular shape by expanding the central part of the thrust block 3, is interposed therein, and a wear ring 53a is fitted onto the surface facing the side gear 49 to provide pressure resistance.

On the other hand, a thrust washer 50 is interposed between the back surface 49a of both side gears 49 and the thrust disk 55, and the peripheral edge of the thrust disk 55 is attached to the inner surface of the small inner diameter portion 21d formed on both sides of the inner circumferential surface of the differential case 21. The axially outward position is regulated by making contact with each other. As a result, the thrust load acting on the side gear 49 from the meshing portion with the pinion gear 39 is received, and a specified pack lash is ensured. In this state, it is desirable that a small gap be formed between both the side gears 49 and the thrust block 53.

A differential limiting mechanism is constructed symmetrically to such a differential gear mechanism as follows.

A clutch disc 57 as a clutch mechanism is located behind the thrust 1-disc 55 and includes a disc member 57a that engages in the rotational direction with a spline 59 formed in the small inner diameter portion 21d of the differential case 21, and an outer periphery of the shaft portion of the side gal 149. The disk member 57b, which is engaged with the spline 61 formed in the rotational direction, is alternately arranged. A push ring 63 is in contact with the terminal end of the clutch disc 57. The push ring 63 is slidably fitted into the drive shift shaft 47 and abuts against the inner end of the push sleeve 45.

Adapters 65 are fixed to both left and right ends of the differential carrier 27 with bolts 67. The adapter 65 has a stepped bore 69 as a cylinder part whose diameter expands inward in three stages.
is formed concentrically with the drive shaft 47, and is slidably engaged with the piston member 75 via seal rings 71 and 73, thereby forming a hydraulic actuator 77 as a hydraulic actuator. A ball bearing 79 is fitted on the inner surface of the large diameter side of the piston member 75, and the push sleeve 4
The impeller race 79a is rotatably supported by the small outer diameter part /I5a formed at the rear end of the small outer diameter part 4.
It is in contact with the inner end of 5a.

Pressure hydraulic oil can be supplied to the back side of the piston member 75 through an oil passage 81 formed in the adapter 65.

The drive shaft 47 has a flange 47a outside the differential carrier 27, and these left and right flanges /47
Left and right rear axles 17 are connected to a.

A booster 83 is provided for supplying pressurized hydraulic oil to the cylinder portion 69.

This booster 83 has a cylinder 8 as shown in FIG.
5 and a piston member 87.

The cylinder 85 has a rod cover 89 on one side, a head force bar 91 fitted on the other side, and a stop ring 93.
It is prevented from falling out.

The piston member 87 includes a piston portion 87a and a rod portion 87b having a smaller diameter than the piston portion 87a. The piston portion 87'a is fitted into the cylinder 85 so as to be able to be repelled, and the 1-1 rod portion 87b is slidably supported by the rod cover 89.

A sealing member 95 is provided on the inner periphery of the cylinder 85 in the piston portion 878', and a first pressure chamber 97 is formed between one side of the piston portion 87a and the head force bar 91. Then, the oil passage 9 formed in the head force bar 91
9 is connected to a hydraulic pump 101 which is a hydraulic pump.

Further, a sealing member 103 is provided on the rod portion 87b with respect to the rod cover 89, and a second pressure chamber 105 is formed between the rod cover 89 and the other side surface of the piston portion 87a. . And cylinder 8
An oil passage 107 is formed on the rod cover 89 side of the adapter 65 , and is connected to the oil passage 81 of the adapter 65 and communicates with the cylinder portion 69 of the hydraulic actuator 77 .

Therefore, a closed passage is formed between the second pressure chamber 105 and the cylinder portion 69, and hydraulic oil is sealed therein.

The cross-sectional area A of the second pressure chamber 105 is the same as that of the first pressure chamber 9.
It is formed to have a small area compared to the cross-sectional area B of 7. Therefore, the working pressure of the hydraulic fluid in the second pressure chamber 105 can be doubled with respect to the pump pressure applied to the first pressure chamber 97.

A spring 109 is interposed between the inner surface of the mouth cover 89 and the other side surface of the piston portion 87a, and when no pump pressure is acting on the first pressure chamber 97, the head of the piston member 87 is moved toward the force bar 91 side. Slight stroke of
The piston member 87 is biased toward the head force bar 91 while leaving behind.

-1 2- Furthermore, the rod portion 87b is provided with a stop portion 111 that restricts the stroke of the piston portion 87 toward the rod cover 89 side.

Furthermore, the piston member 87 has a first pressure chamber 97 and a second pressure chamber 97.
An oil passage 113 is formed that runs parallel to the pressure nozzle J chamber 105.
This oil passage 113 is provided with a poppet-type check valve 115. This check valve 115 is pressed against the seat surface 87c of the piston portion 87a by a built-in spring 117 to prevent backflow of hydraulic oil. Note that the check valve can also be constructed of a steel ball and a spring.

Next, the operation of the above embodiment will be explained.

The clutch disc 57 is always loose and the differential case 2
1 and the side gear 49, the differential gear mechanism can drive both drive shafts 47 while giving them a required angular velocity difference. Here, when one wheel starts idling, when pressure oil is supplied from the hydraulic pump 101 to the first pressure chamber 97 via the oil passage 99, the piston member 87 moves to the spring 1. 09 moves to the left in FIG. will be sent. This pressure oil causes the left and right piston members 75 to be displaced inwardly,
The clutch disc 57 is connected to the clutch disc 57 via a ball bearing 79, a push sleeve 45, and a push ring 63, respectively.
This pressing force is transmitted from the thrust disk 55 to the thrust block 53 via the side gear 49 and received there. Therefore, the clutch disk 57, the disk member 57a. 57b are mutually provided, thereby connecting the differential case 21 and the left and right side gears 45.
are frictionally engaged and relative rotation is suppressed.

In the power transmission device that functions as described above, the cylinder portion 69 of the hydraulic actuator 77 and the second
Pressure chamber 1. 0.05 oil. When air is to be vented from the hydraulic oil, the air vent plug provided in the cylinder portion 69 is loosened and pressure Kt+ is sent from the hydraulic pump 101 to the booster 83. This pressure oil flows into the cylinder portion 69 through the check valve 115, and the air accumulated in the six cylinder portions exits in the form of bubbles.

In this way, the booster 69 and the hydraulic actuator 77
Since the air can be removed at the same time, the air removal work becomes easier.

When the pressure in the six cylinder parts increases due to temperature rise, the check valve 115 opens when the piston member 83 moves the full stroke due to this pressure, and the pressure oil in the cylinder part 69 flows into the second pressure chamber 105 and into the oil passage. 107, and is discharged through the first pressure chamber 97.

[Effects of the Invention] As is clear from the above explanation, according to the structure of the present invention, since the operating pressure is applied to the hydraulic actuator via the booster, a small pressure hydraulic bomb can be used. High working pressure can be obtained. Therefore, the hydraulic pump can be made smaller and lighter.

In addition, since a check valve is installed in the booster, air can be removed from the booster and the hydraulic actuator at the same time, making it easier to bleed air.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a power transmission device according to an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of a differential device, Fig. 3 is a longitudinal sectional view of a booster, and Fig. 4 is a diagram showing this embodiment. FIG. 5 is a cross-sectional view of a conventional power transmission device, which is a skeleton mechanism showing the power transmission of the vehicle used. 77...Hydraulic actuator (hydraulic actuator)
83... Booster 87... Piston member 115... Check valve

Claims (1)

[Claims] The hydraulic actuator is provided with a pressure booster that receives pump pressure from the hydraulic pump and outputs a hydraulic pressure amplified by the cross-sectional area difference of the pistons, and this pressure booster is provided with a check valve, and the hydraulic actuator and the pressure booster are provided with a check valve. A pressure increase transmission device characterized in that when air is removed from the device, pressure fluid from a hydraulic pump can be sent to a hydraulic actuator.