JPH0221061A - Oil pressure control device for transfer - Google Patents

Abstract

PURPOSE:To aim at the reduction of the number of parts by mounting a valve body held in the liquid tight condition to a case, and forming a device so that a part housing spool valves is located inner side than a mounting face to the case of the valve body under that condition. CONSTITUTION:A valve body 21 is attached on a mounting eye 40 on the outer wall 38 of the recessed part formed in a transfer case 20 through a mounting face 24 formed on the all around of the outer part, held in a liquid tight condition. Consequently, an opening part of the recessed part 39 of the case 20 is blocked through a plate 29 and a gasket 30 so that the oil of an upper body 22 and a lower body 23 is not leaked. Under this condition, a housing part housing spool valves V1-V3 is inserted in the recessed part 39, projecting to the side of the case 20 inner than the mounting face 24. Consequently, even if the oil is leaked from the opening part of the holl through which the spool valves V1-V3 were inserted into the valve housing part, the oil is leaked only to the recessed part 39 without the leakage to the outside so that an oil pan is eliminated.

Description

[Detailed description of the invention] Industrial application field This north gate transmits power from the front export power shaft to the rear export power shaft,
This relates to a hydraulic control device in transfer I that transmits data from the rear export force shaft to the export force shaft.

As is well known in the art, in a four-wheel drive vehicle, a part of the torque given from the engine to the rear export power shaft through the transmission is distributed to the front export power shaft in transfer 1, or is given to the 0h export power shaft. It is configured to distribute a portion of the torque to the rear export power shaft in a transfer, and its four-wheel drive types can be broadly divided into so-called part-time four-wheel drive and full-time four-wheel drive. . Part-time four-wheel drive is a configuration that changes between two-wheel drive and four-wheel drive by intermittent transmission of torque to the front wheels or rear wheels, and therefore the torque distribution ratio is 100% higher than the ratio determined by the mechanism of transfer 1. There are two types: is a ratio determined by the transfer mechanism, but if any wheel is idling, a condition called "torque loss" occurs, and torque is no longer transmitted to wheels other than the idling heavy wheel.

Incidentally, it is preferable that the torque distribution ratio between the front and rear wheels of a four-wheel drive vehicle is set according to driving conditions such as when accelerating, braking, climbing, and when driving on a low μ road (a road surface with a small coefficient of friction). Because there are only a few types of torque distribution ratios that can be set in the time four-wheel drive 111J device or the full-time four-wheel drive!IJ device that simply provides a center differential, it is difficult to control the torque distribution simply on and off. However, it is not always possible to obtain a torque distribution ratio that matches the driving conditions.For this reason, recently, for example,
As described in Japanese Patent No. 2-245313, a power transmission device for a four-wheel drive vehicle that is configured to change the torque distribution ratio between front and rear wheels in multiple stages has come into use. This type of power transmission device provides a friction clutch between two members in the center differential that differentially operates the Ifi rear wheels, such as the differential case and one side gear, and the pressing force for engaging the friction clutch is controlled by hydraulic pressure. By adjusting the transmission torque capacity by the friction clutch, the degree of differential restriction is changed, thereby controlling the torque distribution ratio between the front and rear wheels. The pressing force for engaging the friction clutch can be controlled by adjusting the oil pressure itself supplied to the hydraulic servo attached to the friction clutch, and by providing the hydraulic servo with pistons with different pressure receiving areas. It can also be controlled, but in any case, a hydraulic control device such as a pressure regulating valve or a switching valve is required.

In the above-mentioned Japanese Patent Application No. 62-245313, a spool valve is incorporated inside the transformer 71 case as a hydraulic control device for transfer, and the supply of hydraulic pressure to the boost boat is controlled on and off by a solenoid valve. By doing so, the spool valve is operated, thereby changing the hydraulic pressure supplied to the hydraulic servo of the 1'8I friction clutch for differential limiting.

However, in the configuration in which the valve is incorporated into the transfer case, there is a restriction on the number of spools that can be accommodated, for example, and as a result, the control pattern is limited, resulting in the inconvenience that necessary and sufficient control cannot be performed. In order to eliminate this inconvenience, a valve body incorporating the required number of valves is constructed separately from the transfer case, and the valve body is placed in a designated area of the transfer case, for example, where it is less affected by flying stones or water. It is conceivable to install it on the top of the

An example of a hydraulic control device having such a configuration is shown in FIG.

That is, the valve body 1 is composed of an upper body 2 and a lower body 3, each of which has a recess formed in a predetermined pattern as an oil passage Open, and the lower body 3 has an oil for regulating pressure and supplying and discharging oil pressure. Three spool valves 4 for switching paths are slidably housed. The upper tenon 2 and the lower body 3 are fastened together with bolts 7 through a plate 5 that is perforated so that the hydraulic path follows a designed path, and gaskets 6 located above and below the plate 5. The body 1 is further fixed to the upper surface of the case 10 by bolts 11 with another plate 8 and a gasket 9 located above and below the plate 8 in between, and is connected to the recess of the case 10 through a through hole formed in the plate 8 and the gasket 9. This forms an oil path Op. An oil pan 12 is provided on the outer circumferential side of the valve body 1 with a predetermined narrowing part, and a gasket 13 is interposed between the flange part and the upper surface of the case 10 to provide fluid flow. It is attached to the case 10 with bolts 14 while maintaining tightness.

Problems to be Solved by the Invention According to the above-mentioned hydraulic system tit'8 shown in FIG. 8, since the oil pan 12 covers the entire valve body 1,
For example, even if oil leaks from the end of the hole in the lower pod 3 into which the spool valve 4 is inserted, no particular problem will occur. On the other hand, however, in the above-mentioned combined hydraulic control device, since the oil pan 12 is essential, there is a problem that the number of parts increases, resulting in an increase in heavy oil and cost. Since it is necessary to provide a certain amount of space between the oil pan 12 and the valve body 1, there is a disadvantage that the oil pan 12 occupies a large space.Furthermore, the oil pan 12 is generally made of a pressed thin steel plate. Therefore, there was a risk that a co-photographing phenomenon would occur and increase vibration and noise.

This optical system was developed in consideration of the above-mentioned circumstances, and the purpose is to provide a hydraulic control system for a transfer system that does not require an oil pan and can reduce the number of parts.

Means for Solving the Problems In order to achieve the above-mentioned purpose, this optical fiber is installed in a case while keeping the valve body in a liquid-tight state, and in that state, the part that accommodates the spool valve is It is configured to be located inside the case rather than the mounting surface to the case. More specifically, this invention:
A plurality of oil passages through which hydraulic pressure is supplied and discharged are formed inside a valve body attached to the upper part of the transfer case, and a spool valve for opening and closing the oil passages is slidably housed in the valve body. In the hydraulic control device, a mounting surface is formed all around the outer periphery of the valve body, and a valve accommodating portion that protrudes from the mounting surface is provided on the inner circumferential side of the back side of the valve body. The spool valve is inserted into the valve accommodating part from the outer surface of the pulp accommodating part, and a recessed part is formed in the upper part of the transfer case with the upper surface of the outer wall as a mounting seat, and the spool valve is housed in the valve accommodating part. The body knife is attached to the transfer case by inserting its pulp accommodating portion into the recess and fixing the attachment surface to the attachment seat of the transfer case while maintaining liquid tightness. It is something to do.

Function: In the hydraulic control device of the present invention, the valve body is attached to the mounting seat on the outer wall soil surface of the recess formed in the transfer case through the mounting surface formed around the entire outer circumference of the valve body while maintaining liquid tightness. The opening of the recess in the transfer case is thus closed off by the valve body to prevent oil from leaking. In this state, the valve accommodating part that accommodates the spool valve protrudes from the mounting surface toward the transfer case and is inserted into the recess of the transfer case. Therefore, for example, the spool valve can be placed in the pulp accommodating part. Even if oil leaks from the opening of the inserted hole, the oil will only leak into the recess sealed by the valve hole and will not flow out. That is, even if there is no oil pan covering the outside of the valve body, it is possible to prevent oil from leaking to the outside, and as a result, by reducing the number of oil pans, it is possible to reduce the number of parts, heavy oil, and cost.

Example An embodiment of this defense will now be described with reference to the drawings.

Fig. 1 is a top view showing one implementation of this optical system, and the hydraulic control 'II+ device shown here is attached to the upper part of the transfer case 20 in a four-wheel drive system, and is used to distribute torque to the front and rear wheels. It is configured to control. That is, FIG. 2 is a diagram showing the mounting position of the hydraulic control device in a vehicle with an engine fI@ type, and is a diagram when the transfer is viewed in the axial direction from the gear shift I side. Therefore, in FIG. 2, the left side is the front side of the vehicle, and the right side is the rear side, the rear wheel drive shaft is installed so as to extend to the right in FIG. 2, and the engine is located on the left side of the transfer case 20. Placed. This l-ransf 7 case 20 is mounted on a vehicle in the attitude shown in FIG. 2, and a hydraulic control IT table device is attached to its upper side. This hydraulic control f
The valve body 21 at the lH position is mainly composed of an upper body 22 and a lower body 23, and the upper body 22 has a groove that serves as an oil passage Op formed on the upper surface side and the lower surface side, and the groove is formed as appropriate. It is a block-shaped member that is provided with a through hole that communicates with the inside thereof, and the entire peripheral portion of the lower surface thereof is a flat mounting surface 24. In addition, as shown in FIGS. 1 and 3, solenoid valves S1 and S2 are tightly attached by bolts 26 through flanges 25 at two locations on the top surface, that is, two locations where grooves serving as oil passages are open. The solenoid valves 31 and 82 are used to switch the oil passages to which hydraulic pressure is to be supplied and discharged. In addition, at a predetermined location on the upper surface side of the upper body 22,
A test boat 28 is formed which is normally sealed by a fixing bolt 27.

On the other hand, the lower body 23 is similar to the upper body 22 described above.
The plate 2 is placed on the lower surface of the
The lower body 23 is attached by bolts 31 with the lower body 9 and the gasket 30 sandwiched therebetween to ensure liquid tightness, and the lower body 23 is constructed as described below. That is, the lower body 23 is a block-shaped part I smaller than the upper body 22, and inside thereof, grooves serving as oil passages Op are formed mainly on the upper surface side, and the plate 2 Q
An oil passage is formed together with the vortex on the upper body 22 side through a hole (not shown) formed in the gasket 30 and Jj. Furthermore, when the lower body 23 is attached to the lower surface of the upper body 22, it protrudes downward from the mounting surface 24 of the upper body 22, and three spool valves V1, V2, and V3 are inserted from the outer surface of the lower body 23. and these spool valves V1. V2 and V3 are slidably housed in the lower body 23.
is the valve housing part. Fig. 1 shows one of the backs of these spool valves V1, V2, and V3, and Fig. 4 shows its accommodation position with a chain line. Similar to the valves in the hydraulic control device, spool valves Vl, V2, V
3 is slidably inserted, and a plug 33 is fitted into the front end of the accommodation hole 32, and the plug 33 is prevented from being removed with a key 34, and the spool valves V1, V2,
A spring 35 is placed between the end of V3 and the plug 33. In addition, these spool valves V1 and V2
.

The oil passage configuration including V3 and its operation will be described later.

A hydraulic supply boat 36 and a hydraulic discharge boat 37 are formed at the lower end surface of the lower body 23 so as to open therein.

On the other hand, in the upper part of the transfer case 20, there is a recess 3 surrounded by a substantially rectangular outer wall 38 and opening upward.
9 is formed, and the upper surface of the outer wall portion 38 serves as a mounting seat 40 having a shape that matches the mounting surface 24 of the upper body 22 described above.The valve body 21 consisting of the upper body 22 and the lower body 23 is , with the mounting surface 24 in close contact with the mounting seat 40 with the gasket 41 in between, the transfer case 2 is attached with the bolt 42.
It is fixed at o. In this state, the lower body 23, which is a valve housing portion, is housed inside the four portions 39. Also, inside the recess 39 of the transfer case 20, as shown in FIGS.
3 and an inflow hole 44 are formed at positions corresponding to the hydraulic discharge boat 37, respectively. Its delivery hole 4
An oil strainer 45 is housed inside the oil strainer 3 , and a sealing material 46 is arranged at the upper end of the oil strainer 45 .
J: Hydraulic supply boat 36
is in communication with the delivery hole 43. In FIG. 1, reference numeral 47 indicates a through hole for handling oil in the three four parts.

Therefore, in the above hydraulic control device, the valve body f-21
By fixing the spool valves V1, V2, and V2 to the transfer case 20 in a liquid-tight state, a completely liquid-tight property is ensured like the open end of the housing hole 32 that accommodates the spool valves V1, V2, and V3. The outer peripheral wall 38 has a frontage such as a drain groove and a drain groove that forms a recess 39 with the upper body 22.
As a result, oil can be reliably prevented from leaking to the outside even without a conventional oil pan.

The hydraulic circuit including the above-mentioned spool valves Vl, V2, and V3 will now be explained. As this hydraulic circuit, for example, the hydraulic circuit proposed in Japanese Patent Application No. 18424/1988 can be used, and its outline will be shown below. As shown in Figure 6. That is, the first spool valve V1 is a pressure regulating valve,
For this spool valve V1, there is a return boat 50 that opens at the part where the spring 35 is arranged, an inlet boat 51 that directly communicates with the hydraulic pressure supply boat 36, and an outlet boat that sends out the hydraulic pressure supplied from the inlet boat 51. 52, a drain boat I/53, a first boost port 54, and a second boost boat 55 are formed, and among these, the outlet boat 52 and the return boat 50 are connected to each other by an oil passage 57 having an orifice 56. It is being Therefore, when hydraulic pressure is applied to the first signal port 54, a first modulating pressure pH is generated in the outlet boat 52 that produces a pressing force that opposes the pressing force caused by the hydraulic pressure, and furthermore, the first modulating pressure pH is generated in the outlet boat 52, and 54 and 55, the second modulating pressure pH12 (> Plm
+) is generated in the outlet boat 52.

The second spool valve V2 is a first switching valve, and is connected to a signal pressure boat 60 located at the end opposite to the spring 35 and an oil passage 61 to the hydraulic supply boat 36. A first inlet port 62 directly communicated with the outlet boat 52 of the pressure regulating valve described above, a second inlet boat 64 communicated with the outlet boat 52 of the pressure regulating valve via an oil passage 63, and either of these inlet boats 62, 64. The first outlet boat 65 and the drain boat 66 are switched to communicate with each other. A second outlet boat 67 is formed which can be switched to communicate with either the A2 inlet boat 64 or the drain boat 66. The signal boat 60 is communicated with the hydraulic pressure supply boat 36 through an oil passage 69 having an orifice 68, and the above-mentioned solenoid valve S1 is disposed in the middle of the oil passage 69. Therefore, when the solenoid valve S1 is turned off to generate oil pressure in the signal pressure boat 60, the spool valve V2 is lowered to the lower side in FIG. and the second outlet boat 1.67 communicates with the drain boat 66. Conversely, when the solenoid valve S1 is turned on to discharge pressure from the signal pressure boat 60, the spool valve V2 is opened as shown in FIG. It moves upwardly by the spring 35, and as a result, the first inlet boat 62 and the first outlet boats 1 and 65 communicate with each other, and the second inlet boat 64 communicates with the second outlet boat 67. It is supposed to be done.

Further, the third spool valve V3 is a second switching valve, and for this, there is a signal pressure boat 70 located at the end opposite to the spring 35, a drain boat 71, and a second switching valve of the first switching valve. A first inlet boat 73 that communicates with the first outlet boat 65 via an oil passage 72, and a first outlet boat that is switched to communicate with either the drain boat 71 or the first inlet boat 73. 74 and the second inlet boat 7 which is communicated with the second outlet boat 67 of the Tj511J) exchange valve via an oil passage 75.
6, and a 27th inlet boat 77 which is switched and communicated with either the first inlet boat 73 or the second inlet boat (76).The signal pressure boat 70 connects the orifice 78 Oil line 7 equipped with
A second solenoid valve S2 is connected in the middle of the oil passage 79, and the first outlet boat 1/74 is directly connected to the hydraulic pressure supply boat 36 via the oil passage 79. The second boost port 55 is communicated with the oil passage 80, and the second outlet port 77 is communicated with the hydraulic discharge boat 37. Therefore the second? Turn off the fm valve S2 and turn off the signal pressure boat 70.
When the hydraulic pressure is generated, the spool valve V3 moves to the lower side in FIG.
communicates with the hydraulic discharge boat 37 via the second outlet boat 77, and on the contrary, the second 'Rfll valve S2
When the signal pressure boat 70 is turned on and pressure is discharged, the spool valve V3 is pushed upward in FIG. communicates with the hydraulic discharge boat 37 via the second outlet boat 77.

Therefore, in the hydraulic circuit shown in FIG. 6, four types of states can be set depending on the on/off combination of each solenoid valve 81, 82, and the second switching valve of the second switching valve
Four types of hydraulic pressure are supplied from the outlet boat 77 to the hydraulic discharge boat 37. On/off of the solenoid valve 81.82
Table 1 shows the relationship between the OFF combinations and the oil pressure obtained by the oil pressure discharge boat 37. In addition,
In Table 1, P[ represents the line oil pressure supplied from the oil pressure supply boat 36.

Table 1 Therefore, the above hydraulic system i! According to 11B, the oil pressure f
The fF boat 37 is connected to, for example, a friction clutch that distributes torque between the front export power shaft and the rear export power shaft, or an ImJ friction clutch hydraulic system that restricts the differential of a center differential that differentially operates the front and rear wheels. If so,
The transmission torque capacity by the friction clutch can be changed in four stages, and accordingly, the torque distribution ratio between the front and rear wheels can be changed in four stages.

If the hydraulic circuit is configured as described above, the hydraulic pressure will be 1
Since the supply and discharge portion is almost limited to the hydraulic pressure supply boat 36 and the hydraulic pressure displacement boat 37, an appropriate hydraulic power source is connected to the hydraulic pressure supply boat 36, and a pressure gauge and an oil reservoir are connected to the hydraulic pressure discharge boat 37. If the valve body F-21 is connected, it is possible to test the valve body F-21 as a single unit.Therefore, a special jig is required when using the valve body shown in Figure 8, which has many frontages as a single valve body, as a counter stain. This makes testing the valve body extremely easy.

An example of a transfer power transmission system in which the differential limiting force is controlled by the hydraulic control device of the present invention is shown in FIG. 7. In other words, 10 differential cases of 100 center differentials (hereinafter referred to as center differentials)
1 is connected to a transmission 104 via a driven gear 102 and a drive gear 103 meshing therewith, and one side gear 105 of the center differential 100 is connected to a ring gear mounting case 106. ring gear 10
7 is attached, and a hypoid gear 109 connected to the rear wheel drive shaft 108 meshes with the ring gear 107.

Is the other side gear 110 in the center differential 100 the front differential 7 ratio ↑? It is connected to the differential case 112 at "J'> 111, where the power is distributed to the left and right front wheel drive shafts 113. The limiting differential limiting clutch 114 is located at a position that limits relative rotation between the differential case 101 of the center differential 100 and the other side gear 110, that is, between the ring gear mounting case 115 to which the triangular gear 102 is attached and the differential case 112 of the front differential 111. It is provided,
Further, a hydraulic servo 116 is provided to engage and release the outside duty limiting clutch 114. Then, the hydraulic pressure generated by the hydraulic pump 117 is regulated to a predetermined pressure by the id+pressure control device 118 and then supplied to the hydraulic servo 116, thereby increasing the transmission i-lux capacity of the differential limiting clutch 114, that is, the differential It is designed to adjust the limiting force.

In the above embodiment, a mounting surface is formed on the upper body 22, and the valve body 21 is fixed to the transformer 71 case via the mounting surface, but the present invention is limited to the above embodiment. The point is that the valve accommodating part only needs to protrude below the mounting surface (in the installed state, the transf. 1 cous 11111). The valve accommodating portion may be configured to protrude below its mounting surface, and the upper body may seal the upper side of the lower pod.

Further, the opening on the transformer seven-door case side that supplies and discharges hydraulic pressure to and from the valve body does not need to be particularly formed in the recess as shown in the above embodiment, but may be formed so as to open into the mounting seat, for example. Correspondingly, an opening for supplying and discharging hydraulic pressure on the valve body side may be provided in the mounting surface.

Effect between lights As explained above, in the hydraulic side 6118 position of this invention,
By mounting the Pal Apo f- in a liquid-tight manner on the mounting seat of the transfer case through the mounting surface formed on its entire outer periphery, the opening where oil flows out or leaks is located within the recess that is covered by the valve body. Moreover, since the valve body is located above the transfer case, there is no need for an oil pan in particular, and as a result, there is no need for an oil pan that covers the entire outer periphery, reducing the number of parts and the resulting weight. - It is possible to reduce costs, and because there is no oil pan, which is a thin hollow container, it is possible to reduce vibration and noise.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a schematic side view of the transfer to show the mounting position of the hydraulic control l+ device, and Fig. 3 is a schematic side view of the transfer to show the installation position of the hydraulic control l+ device. Fig. 4 is a bottom view of the valve body, Fig. 5 is a plan view of the recess formed in the transfer case, Fig. 6 is a hydraulic circuit diagram showing an example of the hydraulic circuit, FIG. 7 is a skeleton diagram showing an example of a power transmission system of a transfer case, and FIG. 8 is a sectional view showing a conventional example of a stepped valve body in the upper part of a transfer case. 20... Transfer case, 21... Valve body 22... Upper body 23... Lower body 24... Mounting surface, 32... Accommodation hole,
38... Outer peripheral wall, 39... Recessed portion, 40...
Mounting seat, 41...gasket, Vl, V2, V
3...Spool valve. Figure 4

Claims (1)

[Scope of Claims] A plurality of oil passages through which hydraulic pressure is supplied and discharged are formed inside a valve body attached to the upper part of the transfer case, and a spool valve that opens and closes the oil passages is slidable on the valve body. In the hydraulic control device for a transfer housed in, a mounting surface is formed all around the outer circumference of the valve body, and a mounting surface is formed on the inner circumference side of the mounting surface of the valve body.
A valve accommodating part is provided that protrudes from the mounting surface, and the spool valve is inserted into the valve accommodating part from the outer surface of the valve accommodating part and is housed therein. A recess is formed as a mounting seat,
The valve body is attached to the transfer case by inserting the valve accommodating portion into the recess and fixing the mounting surface to the mounting seat of the transfer case in a fluid-tight state. Features a transfer hydraulic control device.