JPS6055353B2 - pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control device for controlling hydraulic pressure for operating a hydraulic clutch.

Conventionally, in a hydraulic clutch for connecting and disconnecting the driving force of a marine engine, etc., or for forwarding and reversing the driving force, a hydraulic pump whose pressure increases approximately in proportion to the rotational speed is used as a hydraulic power source, and this hydraulic pump and the above-mentioned hydraulic clutch are connected. A pressure regulating valve that provides relief at a predetermined high pressure was installed in the connected high-pressure oil passage, but since the pressure regulating valve provides relief at approximately the same high pressure whether the marine engine is rotating at low speed or high speed, There is a problem that power loss is large during low speed rotation, and there is also a problem that large noise is generated from the reduction gear, reverse gear, etc. during low speed rotation.

The cause of this noise is that when the above engine rotates at low speed, there is a large torque fluctuation, which causes fluctuations in rotation speed, and the power transmission system after the hydraulic clutch (coupling, propeller shaft, propeller, etc.)
Resonating with the inertial mass of the gear, the meshing tooth surfaces of reduction gears, reversing gears, etc. had gaps such as backlash, so the tooth surfaces came into impactful contact with each other, causing large noise. .
FIG. 2 shows an example of the above-mentioned conventional pressure regulating valve.
The hydraulic pump a is, for example, a gear pump, which sends pressure oil to a hydraulic clutch (not shown) through a high-pressure oil passage b, and a hole c that communicates with the high-pressure oil passage b has an axially slidable member. A spool d is fitted, and the spool d is resiliently pressed by a single spring e, and the oil passage b
When the internal pressure rises, the spring e is pressed to the right in the figure, and when a predetermined high pressure P1 is reached, the pressure oil escapes through the through hole h that communicates with the return oil path g to the tank f. go.

FIG. 1 shows the rotational speed of gear pump a in this case, that is, the rotational speed Nr of the marine engine. p. m. is taken on the horizontal axis and the hydraulic pressure Pk9/Cri of oil passage b is taken on the vertical axis, where N=
500r. p. m. Hydraulic pressure P5OO at low speed rotation of
and N=2000r'. P. m. The hydraulic pressures P2OOOO during high-speed rotation are approximately equal, and as mentioned above, N=
500r. p. m. Even at rotational speeds where torque fluctuations are large during low-speed rotation, the hydraulic clutch never enters a so-called half-clutch state, and the fluctuations in rotational speed due to torque fluctuations are transmitted as they are to the reduction gear, reverse gear, etc. The tooth surfaces of the gears, which had gaps, collided with each other, creating a large amount of noise. Therefore, in order to solve the above problem, a system shown in Japanese Utility Model Publication No. 46-34247 has already been proposed. is used5.

In the above system, a pressure regulating valve is interposed in the high pressure oil passage between the hydraulic pump and the hydraulic clutch, and two pressure chambers are provided between the spool hole of the pressure regulating valve and the spool, as well as two pressure chambers into which pressure oil flows from the high pressure oil passage. forming two drain chambers,
Pressure oil is supplied to the hydraulic clutch from one pressure chamber.

Additionally, a diagonal orifice and a stepped portion are formed in the spool, and when the engine speed is low, pressure oil is discharged from one of the pressure chambers mentioned above through the diagonal orifice and one drain chamber. ing.

When the engine speed increases, pressurized oil is supplied from the one pressure chamber to the other pressure chamber 4 through the orifice, and the spool is moved in the axial direction to move the pressure oil from the one pressure chamber to the step. In this case, the pressure oil is discharged through one of the drain chambers.

However, the above-mentioned method has a problem in that it is extremely difficult to set the number of steps when the pressure of the pressure oil in the high-pressure oil path increases to a desired value, that is, to three or more steps.

In addition, in the above-mentioned device, not only the diagonal orifice and the stepped portion are formed on the spool, but also a land is formed on the spool to form a pressure chamber and a drain chamber for two between the spool holes, and both An orifice chair, etc. must be formed to communicate the pressure chamber,
The structure of the spool was extremely complex.

The present invention has solved the above problems, and its purpose is to easily set the number of stages at the time of pressure rise of pressure oil in a high-pressure oil path to a desired value; and to simplify the structure. It lies in turning it into something.

Therefore, the characteristics of the present invention are that the engine is connected to the transmission device via the hydraulic clutch, and pressure oil is supplied from the hydraulic pump driven by the engine to the hydraulic clutch via the high-pressure oil path. A pressure regulating valve that increases the pressure of the pressure oil in stages as the engine speed increases is connected to the high-pressure oil passage, and the pressure regulating valve is installed in a spool hole so as to be slidable in the axial direction. The spool has a spool on which pressure acts axially on one end surface, and a spool that presses the other end surface of the spool in the axial direction, and an opening for a return oil passage communicating with the tank is formed on the inner peripheral surface of the spool hole. In this system, a blind hole-shaped first discharge oil passage is formed inside the spool in the axial direction from the above-mentioned one end surface, and the amount of high-pressure oil supplied to the high-pressure oil passage increases as the engine speed increases. In order to gradually increase the cross-sectional area of the discharged oil from the first discharge oil passage to the return oil passage, the spool is sometimes A plurality of second discharge oil passages are arranged in parallel in the axial direction and sequentially open to the opening of the return oil passage when the oil passage slides in the axial direction against the spring. The present invention will be explained below based on illustrated embodiments. In FIG. 4, 1 is a marine engine installed in an engine room, which includes an engine main body 2 and a hydraulic reversing speed reducer 3 connected to a rear transmission device.
etc.

The reversing speed reducer 3 is composed of a forward hydraulic clutch 4, a reverse hydraulic clutch 5, a forward speed reduction mechanism 6, a reverse speed reduction mechanism 7, etc.
The output shaft 1 of the engine body 2 is connected to the engine body 2 via the hydraulic clutches 4 and 5.
Hydraulic pump 8 such as a gear pump is connected in conjunction with 2.
is attached to the reduction gear 3. A pressure regulating valve 9 is attached to the high pressure oil passage 13 connecting the hydraulic pump 8 and the hydraulic clutches 4 and 5 through a branched oil passage 14, and the high pressure oil discharged from the hydraulic pump 8 is , the pressure is controlled by the pressure regulating valve 9. In this way, the pressure regulating valve 9 is interposed in the high pressure oil passage 13, and the switching valve 10 is further interposed, and the forward hydraulic clutch 4,
The oil sent from the pump 8 is selectively switched and sent to either the reverse hydraulic clutch 5 or the tank 15.

Reference numeral 16 denotes a spool, one end surface 17 of which is elastically biased by two types of springs 18 and 19, large and small, arranged on the same axis, and the other end surface 20 of which is connected to the high-pressure oil that communicates with the hydraulic clutches 4 and 5. In response to the pressure in the passage 13, the spool is forced to slide inside the spool hole 21 in the right direction in the figure against the springs 18 and 19.

The spool hole 21 communicates with the high pressure oil path 13 via the oil path 14, and as described above, the spool 16 is fitted into the spool hole 21 so as to be slidable in the axial direction.
1, there is a return oil passage 22 communicating with the tank 15.
An opening groove 23 shown as an opening is formed in the spool 11 so as to sequentially open into the opening groove 23 when the spool 16 slides against the springs 18 and 19.
Inside, there are a plurality of internal oil passages 27, 2 shown as second discharge passages, three in the illustrated example, which communicate with the end face 20 on the pressure receiving side.
8, 29 and corresponding openings 24, 25, 26 on the outer peripheral surface of the spool 16 are provided at predetermined intervals in the axial direction. For example, in the case of a circular hole, the diameter of the hole increases gradually and is arranged from right to left. In the axial center of the spool 21, a relatively large-diameter blind hole 30, shown as a first discharge oil passage, is formed in the axial direction from the pressure-receiving side end face 20, and each internal oil passage 27, 28, 29 It communicates with Therefore, when the amount of pressurized oil supplied to the high-pressure oil passage 13 increases with the increase in the rotational speed of the engine body 2, the spool 11 is moved to the spools 18 and 19 by the pressure of the pressurized oil.
each opening 24, 25, 26 by sliding in the axial direction against the
The blind hole 30 is opened sequentially with respect to the opening groove 23.
The flow path cross-sectional area of the discharged oil to the return oil passage 22 increases stepwise, and the amount of discharged oil increases stepwise. Also, opening 2
Numbers 4, 25, and 26 are supposed to have two each, but you are free to use one each. 31 is a spring chamber, which contains large and small double springs 18 and 19;
The spring chamber 31 includes a spring hole 32 formed on the outer side of the same axis as the spool hole 21, and a spring hole 32 formed on the outer side of the same axis as the spool hole 21.
The spring chamber 31 is formed by a plug 33 attached to the opening periphery thereof, and is operatively connected to the return oil passage 22 by an oil passage 34, so that the inside of the spring chamber 31 is maintained at a low pressure. In addition, in the illustrated example, the small spring 19 is attached to the spring adjustment bolt 35.
The outer end portions are pressed against each other, and the pressure when the first opening 24 opens into the opening groove 23 can be adjusted. The large spring 18 has a slightly short force in its free length, and when low pressure is applied to the pressure receiving end surface 20, the large spring 18 does not come into contact, but only comes into contact after the pressure has increased to a certain extent. The spring characteristics are varied.
Note that 36 is a lock nut and 37 is a cap, which are sealed with gaskets 38, 39, and 40. The characteristics of the pressure regulating valve 9 configured as described above are expressed by the polygonal line 41 in FIG.
Indicated by

In other words, the graph in FIG. 3 has the same horizontal and vertical axes as the graph in FIG. 1, and the broken line again shows the conventional characteristic curve 42 in FIG. curve 4
Especially in the low speed rotation to medium speed rotation range than 2L, a low pressure range was achieved, and the hydraulic clutches 4 and 5 were able to be brought close to the hydraulic pressure curve 43 necessary for torque transmission. The position of the spool 16 shown in FIG. 4 corresponds to the inclined portion 44 of the polygonal line 41 in FIG. , the horizontal portion 47 corresponds to the opening 26, and the last horizontal portion 48 corresponds to the open state of the end surface 20, respectively. In addition, among the passage areas of the openings 24, 25, and 26 which have been gradually increased, the passage area of the largest opening 26 is set to be sufficiently large to relieve almost the entire amount of oil discharged from the hydraulic pump 8. It is also possible to obtain the same, and in that case, the number of stepped horizontal portions in FIG. 3 is reduced by one step. Of course, the number of openings 24, 25, 26 can be increased or decreased as desired, depending on the characteristics of the hydraulic clutches 4, 5 and the required hydraulic pressure curve 43.
All you have to do is increase or decrease it accordingly. Next, FIG. 5 shows another embodiment of the present invention, in which the spool 16 of the pressure regulating valve 9
Although the configuration is almost the same as that of the previous embodiment, tank 1
Opening groove 2 of return oil passage 22 to spool hole 21 to 5
3 is provided with a sufficiently large axial width dimension M, and a plurality of openings 24, 25, 2 provided on the outer peripheral surface of the spool 16.
6 and 49 are configured to increase as the spool 16 slides, so that the sum of their flow path areas increases, and as in the previous embodiment, the respective openings 24, 2
5, 26 open into the opening groove 23, the flow does not go through a state where the flow is interrupted, and the openings 24, 25, . . ., which once opened, do not close until the end.

The characteristics in this case are shown in FIG. 3 by a polygonal line 50. As is clear from the figure, the inclined parts 51, 52, and 53 are closer to the horizontal than in the previous embodiment, and the pressure rises more gradually, so that it is possible to approach the curve 43 even more, which is ideal. In FIG. 6, as shown in the polygonal lines 41 and 50, the peak portion 55 of the torque fluctuation curve 54 is at a predetermined torque T because the lines 41 and 50 are close to the required hydraulic pressure curve 43.

In the present invention, this peak portion 55 is cut not only at low speeds but also at medium and high speeds, which improves noise reduction and fatigue life as described below. extension and other effects. That is, in the pressure control device of the present invention, a blind hole-shaped first discharge oil passage is formed inside the spool in the axial direction from the above-mentioned one end surface, and the oil is supplied into the high pressure oil passage as the engine speed increases. When the amount of high pressure oil increases,
In order to gradually increase the flow path cross-sectional area of the discharged oil from the discharge oil passage to the return oil passage, the spool has a first discharge oil passage that reaches the outer peripheral surface of the spool, and the spool resists the spring due to the pressure of high-pressure oil. A plurality of second discharge oil passages are arranged in parallel in the axial direction, which open sequentially to the opening of the return oil passage when the oil slides in the axial direction. ) The number of floors can be easily set as desired by the number of second discharge oil passages, and for example, the pressure of the pressure oil can be easily increased stepwise in three or more stages.

Further, the spool is simply formed with a blind hole-shaped first discharge oil passage formed in the axial direction from one end surface, and a plurality of second discharge oil passages reaching from the first discharge oil passage to the spool outer peripheral surface. often,
The structure of the spool can be simplified, and the overall structure can also be simplified.

[Brief explanation of the drawing]

Fig. 1 is a graph showing the characteristics of a conventional device, Fig. 2 is a sectional view of the conventional device, Fig. 3 is a graph showing the characteristics of the device of the present invention, and Fig. 4 is a graph showing an embodiment of the present invention. An explanatory diagram and an enlarged cross-sectional view of the main parts, FIG. 5 is an enlarged cross-sectional view of the main parts showing another embodiment,
FIG. 6 is a graph showing an example of torque fluctuation. 4, 5...Hydraulic clutch, 9...Pressure regulating valve, 13...High pressure oil path, 15...Tank, 16...Spool , 17, 20...
・End face, 18, 19...Spring, 21...
... Spool hole, 22 ... Return oil path, 2
3... Opening groove, 24, 25, 26, 49...
... opening, 41, 50 ... polygonal line.

Claims (1)

[Claims] 1. The engine is connected to a transmission device via a hydraulic clutch, and pressure oil is supplied from a hydraulic pump driven by the engine to the hydraulic clutch via a high-pressure oil line. A pressure regulating valve that increases the pressure of the pressure oil in stages is connected to the pressure regulating valve, and the pressure regulating valve is installed in a spool hole so as to be slidable in the axial direction, and the pressure of the pressure oil in the high pressure oil passage acts axially on the end surface. A device comprising a spool and a spring that elastically biases the other end surface of the spool in the axial direction, and an opening for a return oil passage communicating with a tank is formed on the inner peripheral surface of the spool hole, and the inside of the spool has a blind hole shape. A first discharge oil passage is formed in the axial direction from the one end surface, and when the amount of high pressure oil supplied to the high pressure oil passage increases as the engine speed increases, oil returns from the first discharge oil passage. In order to gradually increase the cross-sectional area of the oil discharged to the spool, the spool is slid in the axial direction against the spring by the pressure of the high-pressure oil that reaches the spool outer peripheral surface from the first discharge oil passage. A pressure control device characterized in that a plurality of second discharge oil passages are arranged in parallel in the axial direction, and which open sequentially with respect to the opening of the return oil passage when the return oil passage is released.