JPS609464Y2 - Hydraulic supply device for hydraulic clutch - Google Patents

Description

[Detailed description of the invention] This invention is a hydraulic pressure supply device for a hydraulic clutch, more specifically, the spring end for oil pressure setting in a relief valve type pressure regulating valve that sets the clutch working oil pressure is used to increase or decrease the spring load of the spring. A branch flow circuit for receiving a movable spring receiver that is movable within a certain range along the direction of increasing the spring load, and for moving the movable spring receiver by hydraulic pressure in the direction of increasing the spring load, and is supplied to the hydraulic clutch. A branch flow circuit is provided to branch the hydraulic oil and guide it to the movable spring receiver,
The present invention relates to a hydraulic supply device in which a throttle is inserted into the branch flow circuit.

Such a hydraulic supply device is known, for example, from Utility Model Application No. 52-980.
It is already well known as disclosed in Japanese Patent Laid-open No. 51 and Japanese Patent Laid-Open No. 53-458:M, etc., and the oil guided to the movable spring receiver through the above-mentioned aperture causes the spring receiver to adjust to the hydraulic pressure setting spring. Since the spring load of the hydraulic clutch is gradually increased, the hydraulic pressure applied to the hydraulic clutch is gradually increased, thereby eliminating the shock at the start of clutch operation.

In order to quickly drain the hydraulic oil in order to quickly return the movable spring receiver to the position where the spring load of the hydraulic pressure setting spring is minimized, a switching valve is generally used to switch and control the supply and discharge of hydraulic oil to the hydraulic clutch. At the neutral position, the branch flow circuit is configured to connect to the oil tank, and a check valve is installed in parallel with the throttle to allow oil to flow only in the oil drain direction. In the above-mentioned Japanese Patent Application Laid-open No. 53-4583, the above-mentioned restriction is formed in such a check valve. It is also possible to provide a connected drain oil circuit separately from the branch flow circuit.

By the way, since the throttle is intended to gradually increase the clutch working oil pressure by restricting the flow of oil led to the movable spring receiver, there is a risk that it will become clogged with dust mixed in the oil, and the clutch working oil pressure will be slowly increased. The higher you try to increase the aperture, in other words, the smaller the aperture, the greater this risk becomes.

However, in order to eliminate this fear, if the main filter that removes dust from the hydraulic oil supplied to the hydraulic clutch is made of a fine-mesh filter,
This puts a heavy burden on the hydraulic pump for supplying hydraulic fluid, reducing its efficiency.

This invention attempts to solve the above problems.

The hydraulic pressure supply device for a hydraulic clutch of this invention is a hydraulic pressure supply device as described at the beginning, and is installed on the primary side of the throttle in the branch flow circuit to remove dust from the hydraulic oil supplied to the hydraulic clutch. It is characterized by the insertion and installation of an auxiliary filter whose mesh is finer than that of the main filter.

Therefore, according to this invention, a relatively coarse filter is used as the main filter, which does not place an excessive burden on the hydraulic pump and do not reduce pump efficiency, but the oil passing through the throttle is A fine-mesh filter is used to remove dust on the upstream side of the diaphragm, making it possible to use the diaphragm for a long period of time without clogging.

Hereinafter, a specific example of implementing the present invention having the above-mentioned structure and producing the above-described effects will be described with reference to the drawings.

Figures 1-5 show one embodiment, and this embodiment is a device for supplying hydraulic pressure to a single multi-disc hydraulic clutch 1 as shown in Figure 1. 1
Specifically, in an agricultural tractor, the gate for extracting the driving force of the work equipment is installed in the power transmission path that transmits power from the engine to the PTO shaft, and selectively interrupts and disconnects the transmission of power to the PTO shaft. ing.

As shown in Figure 1, the hydraulic supply system has 3 ports, 2
A switching valve 2 is provided at two ports on the primary side of the switching valve 2, and an oil supply circuit 5 that introduces hydraulic oil from an oil tank 3 by a hydraulic pump 4 and a hydraulic oil supply circuit 5 that leads hydraulic oil in the direction of the oil tank 3. An oil drain circuit 6 for returning the oil is connected thereto, and one port on the secondary side of the switching valve 2 is connected to the hydraulic clutch 1 by an oil supply/drain circuit 7.

The switching valve 2 has a neutral position N in which both the oil supply circuit 5 and the oil supply and discharge circuit 7 are connected to the oil discharge circuit 6 and the hydraulic clutch 1 is disengaged;
Operation position I where the oil supply circuit 5 is connected to the oil supply and discharge circuit 7, and the end of the oil discharge circuit 6 is blocked and the hydraulic clutch 1 is engaged.
It is equipped with.

When the switching valve 2 is placed in the operating position I, the hydraulic pressure of the hydraulic oil supplied to the hydraulic clutch 1 is controlled by a relief valve type pressure regulating valve inserted into the IJ-F circuit 8 branched from the middle of the oil supply circuit 5. It is set by 9.

A hydraulic pressure setting spring in the pressure regulating valve 9 described above is used to prevent a shock from occurring due to sudden high hydraulic pressure acting on the hydraulic clutch 1 when the switching valve 2 is moved from the neutral position N to the operating position I. A movable spring receiver 11 whose end can be moved back and forth within a certain range along the axial direction of the spring 10
The branch flow circuit 13 is a branch flow circuit 13 in which a throttle 12 is inserted behind the movable spring receiver 11 and is connected to the relief circuit 8 on the downstream side of the pressure regulating valve 9.
Connected.

Therefore, when the switching valve 2 is moved from the neutral position N to the operating position ■ and hydraulic oil is supplied to the hydraulic clutch 1, the hydraulic oil flow supplied to the hydraulic clutch 1 is branched and the movable spring receiver 11 The branched flow is then throttled by the throttle 12 in the branched flow circuit 13, so that hydraulic pressure gradually acts on the movable spring receiver 11.

Therefore, when the switching valve 2 is moved to the operating position I, the movable spring receiver 11 gradually moves forward, and the hydraulic pressure setting spring 10
The spring load of the pressure regulating valve 9 is gradually increased, and the relief pressure of the pressure regulating valve 9 is increased.
Therefore, the hydraulic pressure applied to the hydraulic clutch 1 is gradually increased to a predetermined set value.

Similarly, as shown in FIG. 1, a main filter 17 is located in the oil tank 3 at the oil suction end of the hydraulic pump 4.
A is provided, and the main filter 17A is used to remove dust from the hydraulic oil supplied to the hydraulic clutch 1.

Although it is customary to provide such a main filter 17A, in particular, in addition to this main filter 17A, an auxiliary filter 17 may be installed by inserting it into the branch flow circuit 13 described above on the primary side of the aperture 12. .

Specifically, this auxiliary filter 17 is a fourth filter, which will be explained later.
, 5 has the structure shown in Figure 5, but the main filter 1
It is said to be finer than 7A, and has a small diameter aperture 1.
The purpose of this oil is to perform a filtration action to filter and separate dirt and the like from the oil so that the dirt and the like do not get stuck in the oil.

As shown in FIG. 1, the oil drain circuit 6 and the relief circuit 8 are merged on the secondary side of the pressure regulating valve 9.
A secondary pressure regulating valve 14 is further inserted in the merging circuit, and lubricating oil is supplied from the primary side of the secondary pressure regulating valve 14 to lubricated parts 15 such as friction elements in the multi-disc hydraulic clutch 1. A lubrication circuit 16 for supply is led out.

The more specific structure of the hydraulic pressure supply device shown in the circuit diagram in FIG. 1 will be explained with reference to FIGS. 2-5. To,
The spool 20 of the switching valve 2 is built into a valve mechanism housing 19 placed on the top surface of the mission case 18 of the agricultural tractor, including an oil passage therebetween. and clutch port 2
The pressure regulating valve 9 is disposed astride the high pressure passage 24 connected to the lubrication port 3 and the low pressure passage 26 connected to the lubrication port 25. They are placed astride each other.

The pressure regulating valve 9 includes a valve body 27 that blocks a gap between a high pressure passage 24 and a low pressure passage 26, and the high pressure passage 24 acts on an oil chamber 28 behind the valve body 27 through an oil hole 27a formed in the valve body 27.
is caused to advance as shown by the chain line in FIG. 2 against the spring force of the oil pressure setting spring 10, thereby relieving oil from the high pressure passage 24 to the low pressure passage 26.
The oil pressure of the high pressure passage 24 is set.

The base end of the oil pressure setting spring 10, whose tip is received by the valve body 27, is received by the movable spring receiver 11 that is slidably provided within the pressure regulating valve case. The aperture 12 is formed by forming a pore in the valve case that communicates the space 29 on the outer periphery of the base end of the case with the inside of the valve case behind the spring receiver 11.

One end of the high pressure passage 24 (the left end in FIG. 2) is connected to the second and third
As shown in the figure, the oil passage 30 is connected to the passage 30 in the top wall of the mission case 18 and then connected to the space 29, thereby communicating with the space 29. The branch flow circuit 13 is constituted by the oil passage 30 and the space 29.

The oil passage 30 has a vertical passage part 30a connected to the high pressure passage 24 and another vertical passage part 30b connected to the space 29 at both ends thereof, and the two ships' direct passage part 30at3ob
An oil passage 30 is completed with a horizontal passage section between them.

A large diameter annular groove 31 is formed at the upper end of the vertical passage section 30a, and the auxiliary filter 17, which is a feature of this invention, is installed in the annular groove 31.

As shown in FIG. 4-5, this auxiliary filter 17 consists of a ring-shaped annular body 32 made of a visible material such as a suitable synthetic resin or rubber, and a circular ring made of a suitable wire mesh or the like. The filter body 33 is constructed by embedding the peripheral edge of the filter body 33 into the annular body 32 during molding of the annular body 32, so that the annular body 32 and the filter body 33 are integrated.

The auxiliary filter 17 is inserted into the annular groove 31 on the upper surface of the mission case 1B, and presses at least a portion of the annular body 32 on the lower surface of the valve mechanism housing 19 as shown in FIG. It is provided.

As shown in FIG. 2, an annular step 34 is provided on the inner circumferential surface of the valve case of the pressure regulating valve 9 in the middle of the valve case to regulate the amount of movement of the movable spring receiver 11. The normal setting oil pressure of the pressure regulating valve 9 is determined by the force of the spring 10 when the spring receiver 11 is advanced until the pressure is adjusted.

The valve case of the pressure regulating valve 9 is divided into three parts in the length direction as shown in FIG. A plate body 36 that extends over the outer surface of the housing 19 is fixed by a fixture 37. A shim 38 is appropriately interposed between the plate body 36 and the outer surface of the valve mechanism housing 19, and the plate body 36 is fixed by a fixture 39. By fixing 36 to the valve mechanism housing 19, the valve case portion 35 is fixed.

Therefore, by replacing the shims 38 or changing the number of shims, it is possible to change the front and rear positions of the valve case portion 35 and the valve body 27 that is installed inside it. Since the initial spring load of 10 is changed, the set pressure of the pressure regulating valve 9 can be changed and adjusted by adjusting the shim 38.

The secondary pressure regulating valve 14 is installed inside the top wall of the mission case 18 at the end of the low pressure passage 26 described above.

In FIG. 2, reference numeral 40 denotes a fixture for fixing the valve mechanism housing 19 to the transmission case 18.

Since the illustrated auxiliary filter 17 is configured as described above, the filter 17 is inserted into the annular groove 31 described above, and the ir*valve mechanism housing 1 is placed on the mission case 1 s.
9, it can be easily inserted into the connection end of the oil passages 24 and 30, and in this installed state, the annular body 32, which is made of flexible material, is connected to the bottom of the annular groove 31 and the mission. Since the outer periphery of the auxiliary filter 17 is sealed in close contact with the lower surface of the case 19, it is reliably prevented that dirt and oil pass through the outer periphery of the filter 17, and the aperture 12 is reliably prevented from clogging.

Next, FIG. 6 shows another embodiment incorporating an auxiliary filter 17' used in place of the auxiliary filter 17, and the auxiliary filter 17' shown in FIG. Then, a filter main body 33' is placed over the hole in the annular body 32' made of a flexible material, and the peripheral edge of the filter main body 33' is embedded in the annular body 32'.
It is configured to be integrated with 2',
The annular body 32' is formed to have an outer diameter that elastically comes into close contact with the inner peripheral wall of the annular groove 41 formed at the end of the oil passage 40.

Therefore, the oil passage 40 constituting the branch flow circuit 13,
The auxiliary filter 17' inserted into the connecting end of 42
The outer circumferential surface of the annular body 32' seals the outer circumferential portion, thereby achieving a reliable filter function.
Further, as shown in the figure, by elastically fitting into the annular groove 41 and maintaining the position, it can be easily installed.

[Brief explanation of drawings]

Fig. 1 is a hydraulic circuit diagram showing an embodiment of this invention, Fig. 2 is a cross-sectional plan view showing the specific structure of the main part of the same embodiment, Fig. 3 is a longitudinal sectional front view of the main part of Fig. 2, and Fig. 4 is a hydraulic circuit diagram showing an embodiment of this invention. 5 is a plan view of the same member, and FIG. 6 is a sectional view showing the main part of another embodiment. 1...Hydraulic clutch, 2...Switching valve,
3...Oil tank, 4...Hydraulic pump,
9... Pressure regulating valve, 10... Oil pressure setting spring, 11... Movable spring receiver, 12...
... Throttle, 13... Branch flow circuit, 17A...
...Main filter, 17...Auxiliary filter.

Claims (1)

[Scope of utility model registration request] The end of the oil pressure setting spring 10 in the relief valve type pressure regulating valve 9 that sets the clutch working oil pressure is connected to the spring 1.
The movable spring receiver 11, which is movable within a certain range along the direction of increase/decrease, receives a spring load of 0, and this movable spring receiver 11
A branch flow circuit 13 for hydraulically moving the spring load in the direction of increasing the spring load, which branches the hydraulic oil flow supplied to the hydraulic clutch 1 and guides it to the movable spring receiver 11. A hydraulic supply device is provided in which a throttle 12 is inserted into the branch flow circuit 13, and the hydraulic oil is placed on the primary side of the throttle 12 in the branch flow circuit 13 to supply hydraulic oil to the hydraulic clutch 1. To remove dust, use the auxiliary filter 1, which is finer than the in-filter 17A.
Hydraulic pressure supply device for hydraulic clutch, which is installed by inserting 7.