JPS6238039Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic pressure adjustment mechanism for a reduction/reversing machine and the like.

First, the overall hydraulic system of the speed reduction/reversing gear will be explained with reference to Figure 1. 1 is the hydraulic oil pump, 2 is the forward clutch, 3 is the reverse clutch, 4 is the forward shaft lubrication part, and 5 is the reverse shaft lubrication part. . Both clutches 2,
3 communicates with the pump 1 via supply oil passages 6, 7 for the front and reverse clutches, a clutch switching valve 8, and a pump side main oil passage 9. Both lubricating parts 4 and 5 include lubricating oil passages 10 and 11 for the front and reverse axes, a lubricating oil strainer 12, a lubricating oil cooler 13, and a primary pressure regulating valve (hydraulic oil pressure regulating valve) 1.
4. Communicates with the pump 1 via the lubricating oil source oil path 15 and the source oil path 9. The suction side of the pump 1 communicates with an oil tank 17 via a strainer 16. 18 is a secondary pressure regulating valve (lubricating oil pressure regulating valve).

The primary pressure regulating valve 14 is equipped with a loose fitting valve mechanism 20, and this loose fitting valve mechanism 20 is connected to the cylinder 2.
1. It consists of a piston 22, a spring 28, etc., and the inside of the cylinder 21 is connected to a supply oil passage 24 for operating the loose fitting valve mechanism and a source oil passage 25 (imaginary line) for the loose fitting valve mechanism via the inside of the switching valve 8. It is switchably connected to the drain oil path 26. Source oil passage 25 for loose fitting valve mechanism
is connected to the pump side source oil passage 9, and is connected to the drain oil passage 2.
6 leads to an oil tank 17. Loose fitting valve mechanism 20
For example, when the oil pressure in the cylinder 21 is 0 kg/cm ² , the set oil pressure value of the primary pressure regulating valve 14 is set to 3, for example.
Kg/cm ² is maintained at cylinder 2.
As the oil pressure in the primary pressure regulating valve 14 increases and the piston 22 is pushed in against the spring 23, the set oil pressure value of the primary pressure regulating valve 14 is increased. In order to supply oil to the loose-fitting valve mechanism 20 more slowly than in the past, for example, the oil passage 25 of the switching valve 8
A diaphragm 27 (imaginary line) is provided at the inlet portion.

The purpose of providing the above-mentioned loose-fitting valve mechanism 20 is to suppress the hydraulic pressure at a low level when the clutches 2 and 3 start pressing, that is, when the clutch plates begin to press against each other as in the half-clutch state. To prevent shock when the clutch is engaged, and after the clutch is connected, make sure that there is enough hydraulic pressure (e.g. 15 kg/kg).
cm ² ).

However, in a structure that includes the original oil passage 25 and restricts the oil supply to the loose fitting valve mechanism 20 by the throttle 27, hydraulic oil starts to be supplied to the clutch supply oil passages 6 and 7 by the switching operation of the switching valve 8. At the same time (at the stage before the start of the clutch pressing operation), oil supply to the loose fitting valve mechanism 20 is started. That is, in Fig. 2, if t ₀ is the time when the switching valve 8 (Fig. 1) is switched to the forward or reverse position, t ₁ is the start of the clutch pressing operation, and t ₂ is the time when the clutch connection is completed, then as described above, In a structure in which only the source oil passage 25 and the throttle 27 are provided, as shown by the imaginary line in Fig. 2, the hydraulic pressure starts to rise at t ₀ when the switching valve is switched, and reaches its lowest level at t ₁ when the clutch press-fitting operation starts. The oil pressure has increased above the set oil pressure value (for example, 3Kg/cm ² ). Therefore, it cannot be said that the shock at _t1 at the start of the clutch pressing operation can be sufficiently prevented.

The purpose of this invention is to more reliably prevent shock at the start of clutch pressing operation.The gist of this invention is to ensure that the hydraulic oil pump A modulating valve is provided which can close due to the pressure difference between the supply oil passage and stop the supply of oil for increasing the set pressure to the loose fitting valve mechanism. The present invention will be explained below based on the drawings.

Fig. 3 is a side view of the spool 30 of the switching valve 8 to which the present invention is applied, and Figs. 4a and 4b show the states at the neutral position and the forward position, respectively.
The sectional views, FIGS. 5a and 5b, are cross-sectional views taken from FIG. 3, showing the neutral position and the forward position, respectively.

In FIG. 3, the spool 30 is rotatably fitted into the valve hole 32 of the valve body 31.
A main oil passage 33 extending in the axial direction is formed at the axial center of the cylinder. One end of the main oil passage 33 (left end in Figure 3) communicates with a cylindrical oil chamber 34 perpendicular to the spool 30,
The other end of the main oil passage 33 is closed by the side wall of the valve box 31. A forward clutch oil passage 35 and a reverse clutch oil passage 36, which are perpendicular to the spool 30, communicate with an intermediate portion of the main oil passage 33. The oil passages 35, 36 for both clutches are formed at intervals in the axial direction, and the oil passages 35, 36 are formed at a constant circumferential angle with respect to each other around the spool axis, for example, as shown in FIG. 4a. It is formed to separate the 37
is a drain annular groove, and the drain oil passage 26 (first
(Fig.) is in constant communication. The drain annular groove 37 has a drain groove 3 extending parallel to the axis to the left in FIG.
8 are in communication, and the left end portion of the drain groove 38 is in communication with a drain groove 41 (FIGS. 4a and 4b) on the back side of FIG. 3 via a circumferential groove 40. Further, the drain groove 38 has a drain groove portion 38a that is bent in the circumferential direction at the same cross-sectional portion as the forward clutch oil passage 35 (− cross-sectional portion in FIG. 3). 6 and 7 in Figure 3 are as explained in Figure 1,
These are supply oil passages for the front and reverse clutches on the valve box 31 side, and 9 is the original oil passage on the hydraulic oil pump 1 side.

In FIG. 5a, a modulating valve support cylinder 42 is located near the outer periphery of the spool of the cylindrical oil chamber 34.
A modulating valve 43 is fitted through the support cylinder 42, and is urged in the valve opening direction (in the direction of the reverse arrow A) by a spring 44, and the valve collar 43a is locked to the edge of the support cylinder 42. An annular oil passage 45 opened and closed by the flange 43a includes an oil passage 46 and an arc-shaped cutout chamber 4.
7, the loose fitting valve mechanism 20 (first
It communicates with a first oil groove 48 for supplying hydraulic oil to the hydraulic fluid. This first oil groove 48 extends parallel to the axis of the spool 30, and as shown in FIG. 50.

The modulating valve 43 (FIG. 5a) is formed into a thick-walled cylindrical shape, and the oil passage 51 on the inner peripheral surface thereof
, the cylindrical oil chamber 34 and the pump side circular arc notch chamber 52
The notch chamber 52 is always in communication with the pump side source oil passage 9. The annular pressure receiving area of the modulating valve 43, for example, the annular area viewed in the direction of arrow A, is set as follows. That is, when the oil pressure value P ₁ of the source oil passage 9 is greater than the oil pressure value P ₂ of the oil chamber 34 by 3 kg/cm ² or more, the oil pressure difference P ₃ closes against the spring 44 as shown in FIG. 5b. The area is such that the valve state (the state in which the annular oil passage 45 is closed) can be maintained. Therefore, as the oil pressure difference _P3 becomes smaller, the modulating valve 43 opens, and when the oil pressure difference _P3 is O, the modulating valve 43 is fully opened as shown in FIG. 5a. In addition, in FIG. 5a, 54 is a bolt for fixing the support tube 41.

4a and 4b, the supply oil passage 24 for operating the loose fitting valve mechanism explained in FIG. 1 is connected to the spool 3.
0 rotation operation, the first and second oil grooves 48, 49
and the drain groove 41 can be selectively communicated with each other. The supply oil passage 6 for the forward clutch can selectively communicate with the oil passage 35 for the forward clutch and the drain groove 38 by rotating the spool 30.

Next, the operation will be explained. As shown in FIGS. 4a and 5a, when the spool 30 is in the neutral position, the supply oil passage 24 for operating the loose fitting valve mechanism (the 4th a
) is in communication with the drain groove 41, and the loose fitting valve mechanism 20
The oil pressure in the cylinder 21 (FIG. 1) is maintained at O. Therefore, the set oil pressure value of the primary pressure regulating valve 14 is maintained at the minimum value of 3 kg/cm ² . On the other hand, the first oil groove 48
(Fig. 4a) and the second oil groove 49 are closed, and both clutch oil passages 35 and 36 communicating with the main oil passage 33 are also closed, so the oil pressure value P ₂ of the oil chamber 34 and the original The oil pressure values P ₁ of the oil passage 9 are equal, and the modulating valve 43 is fully opened by the spring 44.

When the spool 30 is rotated in the direction of arrow F from the neutral position shown in FIGS. 4a and 5a to the forward position shown in FIGS. 4b and 5b, the forward clutch oil passage 35 and the forward clutch supply oil passage 6 are brought into communication. That is, the hydraulic oil from the source oil passage 9 is transferred to the notch chamber 52 and the modulating valve 4.
The oil begins to be supplied to the forward clutch 2 (FIG. 1) through the oil passage 51, the main oil passage 33, the forward clutch oil passage 35, and the forward clutch supply oil passage 6 in the forward clutch 3. From the start of hydraulic oil supply to the forward clutch 2 to the start of the pressure contact operation of the forward clutch 2, almost no load is applied from the forward clutch 2 to the hydraulic oil in the main oil passage 33, and therefore the main oil passage 33 and oil chamber 34 to the modulating valve 43 in the direction of the reverse arrow _A is considered to be 0 kg/cm ² . On the other hand, the oil is connected to the modulating valve 43 from the source oil passage 9. Since the oil pressure value P ₁ in the direction of arrow A is 3 kg/cm ² , the modulating valve 43 is in the closed state (the state shown in FIG. 5b), and the hydraulic oil path from the oil chamber 34 to the loose fitting valve mechanism 20 is closed. close. That is, when the spool 30 is switched to the forward position, the modulating valve 43 closes, stopping the supply of hydraulic oil to the loose-fitting valve mechanism 20, and maintaining the primary modulation until the forward clutch 2 starts the pressing operation. Set oil pressure value of pressure valve 14 to 3Kg/
Maintain at ^cm2 . The hydraulic characteristics during this period are shown in Figure 2.
It is represented by a graph shown by a solid line from t ₀ to _{t 1} .

When the forward clutch 2 starts to press, a load starts to be applied from the forward clutch 2 to the hydraulic oil in the main oil passage 33 and the oil chamber 34, the modulating valve 43 begins to open, and the oil passage 46, from the oil chamber 34, Hydraulic oil begins to be supplied to the loose fitting valve 20 through the notch chamber 47, the first oil groove 48, and the supply oil passage 24 for operating the loose fitting valve mechanism, and the set oil pressure value of the primary pressure regulating valve 14 increases. That is, since the pressing operation of the forward clutch 2 starts when the oil pressure value of the source oil passage 9 is the lowest oil pressure value (3 kg/cm ² ), there is almost no shock at the start of the pressing operation.

After the forward clutch 2 starts pressing, the set oil pressure value of the primary pressure regulating valve 14 increases to a specified oil pressure value (for example, 15 kg/cm ² ) by the action of the loose fitting valve mechanism 20. The changes in hydraulic characteristics in this case are shown in the section shown in Figure 2.
It is shown by a solid line from _t1 to _t3 . In the middle of this section, for example at _t2, the forward clutch 2 is completely engaged.

When connecting the reverse clutch 3, the spool 30 is rotated in the direction of arrow R from the neutral position shown in FIGS. 4a and 5a, and the reverse clutch oil passage 36 and the reverse clutch supply oil passage 7 (first (Figure). At this time, the supply oil passage 24 for operating the loose fitting valve mechanism
communicates with the second oil groove 49. The operation of the modulating valve 43 is similar to that for the engagement of the forward clutch 2.

As explained above, the present invention has a hydraulic oil pump 1.
The supply oil passages 6 and 7 for the clutch are connected via the switching valve 8, and the respective lubricating parts 4 and 5 are connected via the pressure regulating valve 14. A modulating valve 43 is provided in the switching valve 8, and a supply oil passage 24 for operating the operating part of the loose-fitting valve mechanism 20 is communicated with the pump 1 via the modulating valve 43 to supply oil for the clutch. From the start of oil supply to roads 6 and 7, clutch 2,
Until the pressure welding operation starts in step 3, the modulating valve 43 closes due to the difference in the hydraulic pressure values from the hydraulic oil pump 1 applied to the modulating valve 43 and the oil supply passages 6 and 7, and the valve 43 closes to the loose fitting valve mechanism 20. Since the oil supply for increasing the pressure is stopped,
The clutch pressing operation is reliably started when the oil pressure is low, and a shock at the start of the clutch pressing operation can be reliably prevented. That is, the clutches 2, 3 are always connected smoothly, and the life of the clutches 2, 3, etc. is extended.

In the embodiment, the minimum hydraulic pressure value of the pressure regulating valve 14 is set to 3 kg/cm ² , but this may be set to an appropriate value such as 5 kg/cm ² depending on the size of the speed reduction/reversing device.

Furthermore, the present invention can be applied not only to speed reduction/reversing gears, but also to various power transmission devices having clutches and lubricated parts.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic system diagram of the speed reducer/reverser, Fig. 2 is a hydraulic characteristic diagram, Fig. 3 is a side view of the switching valve spool to which the present invention is applied, and Figs. - and - sectional views, Figures 4b and 5b are the third position in the forward position, respectively.
It is a -, - sectional view of the figure. 1... Hydraulic oil pump, 4, 5... Lubrication part,
6, 7...Supply oil passage for clutch, 14...Pressure regulating valve, 20...Slow fitting valve mechanism, 24... Supply oil passage for operating the loose fitting valve mechanism, 43...Modulating valve.

Claims (1)

[Scope of utility model registration request] The supply oil line for the clutch is connected to the hydraulic oil pump via a switching valve, and each lubricating part is connected via a pressure regulating valve.The pressure regulating valve is equipped with a loose fitting valve mechanism for automatically adjusting the set pressure. is equipped with a modulating valve, and the supply oil passage for operating the operating part of the loose-fitting valve mechanism is communicated with the pump via the modulating valve, from the start of oil supply to the supply oil passage for the clutch to the start of the clutch press-fitting operation. During the deceleration, the modulating valve closes due to the pressure difference between the hydraulic oil pump and the clutch supply oil path, and the supply of oil for increasing the set pressure to the loose-fitting valve mechanism is stopped. Hydraulic adjustment mechanism for reversing machines, etc.