JPH03272329A - Low speed valve for clutch oil pressure control device - Google Patents

Abstract

PURPOSE:To enable crawling operation for trolling by setting the inclination, in the rotating direction, of the front half of a boundary adjacent to a control drain outlet at the time of the turning angle of a second spool being small to be larger than the inclination of the rear half part of the boundary adjacent thereto at the time of the turning angle being large so as to lower propeller rotating speed in a wide lever angle range. CONSTITUTION:A boundary 35 between a land part 31 and a groove 32 has different inclined angles from a middle point 35A serving as a border. The inclination D to the peripheral direction is larger in a part from an end part close to a position 30A at the neutral time to the middle point 35A than that in a part from an end part close to the maximum angle position 30B of a control drain outlet 30 to the middle point 35A. When a trolling lever 3 is rotated into the maximum angle position from its neutral position, a control chamber 20 is communicated with the outlet 30 from the groove 32, so that oil pressure in the control chamber 20 is lowered, and therefore a spring 7 is extended to move a second spool 6 onto the lever shaft 4 side. As a result, the spring force applied to a first spool 5 by the spring 7 is lowered, and the feed oil pressure at an inlet 10 is therefore reduced and also the oil pressure at an outlet 11 is lowered to generate sliding to the friction plate of a clutch. A ship is thus navigated in the crawling state.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clutch hydraulic control device used for a hydraulic clutch of a ship, etc.
Related to low speed valves used in devices.

[Prior Art] Generally, clutch hydraulic control devices used in fishing boats, etc.
A low-speed valve (trolling valve) is provided in the middle of the circuit that connects the oil pump and the clutch switching valve. This low-speed valve is capable of selectively setting a hydraulic pressure that allows the clutch to be fully engaged (normal connection hydraulic pressure) and a hydraulic pressure that allows the clutch to be incompletely engaged (half-clutch engagement hydraulic pressure).

[Invention or problem to be solved @] However, in conventional low-pressure valves, as the operating angle (lever angle) of the operating lever increases, the rate of change in the outlet oil pressure of the low-pressure valve increases. -More specifically, in the range where the lever angle of the operating lever is small, the amount of change in the low pressure valve outlet oil pressure (hydraulic pressure supplied to the clutch) with respect to the increase in lever angle is relatively small, but the amount of change in the lever angle is relatively small. In a range where the pressure is large, the outlet oil pressure of the low pressure valve tends to change relatively large even if the control lever is operated by a small angle.The reason for this is explained later, but the low pressure valve with such characteristics If this is adopted in a ship's clutch hydraulic control system, it is difficult to delicately control the clutch hydraulic pressure during trolling operation, and the problem arises that it is difficult to perform the desired slow-speed operation.

The present invention aims to provide a structure that eliminates the above-mentioned problems.

[F stage for solving the problems] To achieve the above object, the present invention provides a main hydraulic circuit extending from a hydraulic inlet to a hydraulic outlet, a main drain circuit connecting the main hydraulic circuit to a main drain outlet, and a main hydraulic circuit extending from a hydraulic inlet to a hydraulic outlet. a first spool that controls the opening degree of the drain circuit; a compression spring that is connected at one end to the first spool and biases the spool in a direction to decrease the opening degree; and a second spool that is connected to the other end of the compression spring; A control chamber facing the second spool and for applying hydraulic pressure in the direction of decreasing the opening to the spool, a communication circuit connecting the control chamber and the main hydraulic inlet, and a control chamber to the control drain outlet for freely adjusting the opening. and an operating mechanism for rotating the second spool around a center line parallel to the opening decreasing direction, the control circuit being provided on the outer periphery of the second spool. the second spool is provided with a land portion located in the opening decreasing direction with respect to the groove and capable of closing the control drain outlet, and the boundary between the runt portion and the groove is defined by a second The angle of inclination is tilted with respect to the direction of rotation of the spool and a direction parallel to the center line, and the front half of the boundary adjacent to the control drain outlet is tilted in the direction of rotation when the rotation angle of the second spool is small. is larger than the angle of inclination of the rear portion of the boundary adjacent to the control drain outlet with respect to the rotation direction when the rotation angle of the second spool is large.

[Example] In Fig. 1, the casing assembly is composed of a plurality of cylindrical or annular members, and the center line O-0
What is the concentric hole or cylindrical space? A governor oil passage joint 2 is connected to one end of the hole, and a lever shaft 4 of a trolling lever 3 is rotatably fitted to the other end.

Inside the hole, a first spool 5 is slidably fitted at a position adjacent to the governor oil passage joint 2, and a second spool 6 is slidably fitted at a position adjacent to the lever shaft 4. It matches. Further, a compression coil spring 7 is interposed between the first spool 5 and the second spool 6.

The casing assembly 1 is provided with a main hydraulic circuit 12 connecting the port 10, the outlet 11, and the two ports.

The population 10 is connected to a hydraulic supply, not shown. The outlet 11 is connected to an operating chamber of a hydraulic clutch via a hydraulic circuit and a switching valve (not shown).

Historically, the casing assembly l is provided with a main drain outlet. The main drain outlet 15 is connected to the main hydraulic circuit 2 via a main drain circuit 6 formed of a gap between the outer periphery of the first spool 5 and the inner periphery of the casing assembly 1 .

An annular valve seat] 7 is formed in the part surrounding the main drain circuit [6] of the casing assembly 1, and a flange [8] that can be seated on the valve seat 17 from the spring 7 side is formed on the first spool 5. ing. In FIG. 1, the portion of the first spool 5 above the low-speed valve center line O-0 is shown in a state away from the flange 18 or valve seat 7, that is, in a state in which the main drain circuit 16 is open. In the lower part, the flange 18 is shown seated on the valve seat 17 to close the main drain circuit 16.

The spring 7 is seated at one end on the side opposite to the valve seat 17 with respect to the spool 5, and urges the first spool 5 in a direction to reduce the opening degree of the main drain circuit 16.

The other end of the spring 7 is seated on one end surface of the second spool 6. The other end surface of the second spool 6 forms a control chamber 20 between the lever shaft 4 and the surrounding case portion. The control chamber 20 communicates with the inlet 10 via a throttle 21 and communication circuits 22 and 14 provided inside the casing assembly 1.

The second spool 6 has a center hole open to the lever shaft 4 side, into which the protruding shaft 25 of the lever shaft 4 is slidably inserted. A groove 26 extending parallel to the center line O-0 is formed on the outer peripheral surface of the protruding shaft 25, and a pin 27 is formed in the groove 26.
It is housed in a radially extending position. The pin 27 protrudes outward from the protruding shaft 25 and fits into the hole of the second spool 6, thereby operating the trolling lever 3 and rotating the lever shaft 4 about the center line O-0. Then, the second spool 6 also rotates in the same direction and by the same angle.

Further, since the pin 27 is slidably inserted into the elongated shaft 26 of the protruding shaft 25, the second spool 6 can freely move in the axial direction (direction parallel to the center line OO) with respect to the lever shaft 4. I can do it.

In the vicinity of the second spool 6, the casing assembly 1 is further provided with a controlled drain outlet 30.

The outer periphery of the second spool 6 is provided with a land portion 31 for closing the control drain outlet 30 and a groove '32 for communicating the control chamber 20 with the control drain outlet 30. The groove 32 is a notched groove provided on the outer peripheral surface of the second spool 6, and has a shape a as shown in FIG.

FIG. 2 is a developed partial view of the outer peripheral surface of the second spool 6. As shown in FIG.

In FIG. 2, the arrow Rh direction indicates the second spool 6 relative to the control drain outlet 30 when the second spool 6 is rotated to the operating position (that is, in the direction of increased opening luh) by the trolling lever 3 in FIG. This is the relative moving direction of the outer circumferential surface of No. 6.

35 is a boundary between the runt portion 31 and the groove 32; in other words, it is a surface forming a step between the land portion 31 and the groove 32. The land portion '31 and the groove 32 are located within this boundary 35.
It is formed to be inclined with respect to both the axial direction and the circumferential direction (R).

Further, 30A indicated by a solid line is a control drain outlet 30 for the outer circumferential surface of the second spool 6 when the second spool 6 is in the neutral position, that is, when no trolling operation is being performed.
It shows the position of 30B is the circumferential position of the control drain outlet 30 relative to the outer peripheral surface of the second spool 6 when the second spool 6 is rotated to the maximum angle within a predetermined range to perform a trolling operation. Of course, as will be clear from the description that will be given later, in actual operation, the boundary 35 will not deviate significantly to the left as shown in FIG. 2 with respect to the control drain outlet 30 located at the position 30B.

According to the embodiment of the present invention, the boundary 35 is the intermediate point 35
The angle of inclination differs with A as the border, and the neutral position is 3.
The inclination angle with respect to the circumferential direction is larger than the part between the end near 0A and the middle point 35A, or the part from the end near the maximum angle position 30B of the control drain outlet 30 to the middle point 35A. There is.

The specific dimensions and specifications of each part mentioned above are set so that each part operates as follows.

When the trolling lever 3 is in the neutral position, the control drain outlet 30 occupies the position 30A of FIG. 2 and is closed by the runt portion 31, and the pressure in the control chamber 20 is maintained high. Therefore, the second spool 6 is connected to the first spool 6 as shown in the F half of FIG.
Move to the spool 5 side as much as possible and directly press the first spool 5 with the tip of the second spool. In this state, the flange 18 of the second spool is pressed against the valve seat 7, so generally there is no communication between the main hydraulic circuit 2 and the main drain Iu1 path, and the high pressure introduced from the inlet 10 is
The oil is directly sent to the outlet 1 via the main hydraulic circuit 12.

Next, when the trolling lever 3 is rotated from the neutral position to the maximum angle position, the control chamber 20 communicates with the control drain outlet 30 via the control circuit 32 (control circuit), so the oil pressure in the control chamber 20 decreases. Therefore, the spring 7 expands and moves toward the second spool 6 or the lever shaft 4, and from the spring 7 to the first
The spring force applied to the spool 5 decreases. the result,
The first spool 5 moves to the second spool 6 side and temporarily separates from the flange 18 or valve seat 17, and the oil is discharged from the main drain circuit 16 to the main drain Taguchi 15.
The hydraulic pressure supplied to the outlet 11 is significantly reduced in pressure and sent out from the outlet 11. In this way, the hydraulic pressure sent from the outlet 11 to the clutch decreases, causing slippage on the friction plates of the clutch.
Ships can perform slow-speed navigation.

In this low speed operation (trolling operation), the boundary 35
Since the trolling lever 3 has a shape as shown in FIG. 2, while the operating angle (lever angle) of the trolling lever 3 is relatively small, the amount of movement of the second spool 6 relative to the amount of increase in the lever angle increases, As the lever angle increases, the amount of movement of the second spool 6 relative to the amount of increase in the lever angle becomes relatively small. The position of this second spool corresponds to the elasticity of the spring 7 and thus to the force with which the flange 18 is pressed against the valve seat 17. As a result, the pressure of the eight openings 11 also changes in accordance with the changing characteristics of the position of the second spool.

The above operating characteristics are illustrated in the graph of FIG.

In FIG. 3, value A is the lever angle when the control drain outlet 30 begins to open, and value B is the maximum lever angle. Then, the pressure at the outlet 11 (trolling pressure) changes as shown in P. More specifically, when the lever angle is a relatively small value (A-C), the rate of change in the trolling pressure P is relatively large. When the lever angle becomes larger than the intermediate value C, the rate of change of the trolling pressure P becomes smaller.

Basically, the friction plate of the clutch is brought into pressure contact with the force corresponding to this trolling pressure P, so the propeller rotation speed of the ship also roughly corresponds to it, and if the engine rotation speed is relatively high (Hl, N2, Nl, N2 ) and when the engine speed is relatively low (Ll, N1, N2), when the lever angle exceeds an intermediate value (e.g. C), the propeller speed becomes sufficiently low and the lever angle changes. The propeller rotation speed will gradually change. As a result, it becomes possible to delicately control the speed of a propeller rotating at low speed.

Incidentally, in the conventional structure, if the boundary (35) is shown in a developed view similar to FIG. 2, the boundary (35) extends linearly over the entire length. As a result, as shown in Figure 4, the rate of change of the trolling pressure p increases as the lever angle increases, and as a result, the propeller rotation speed also increases, as shown by Ω or h, until the lever angle becomes sufficiently large. The speed does not decrease to the desired low speed value, and moreover, in the low speed range, the rate of change of the propeller rotation speed with respect to the lever angle becomes very high. As a result, trolling operations are difficult to perform.

In addition, in FIG. 4, the solid line shows the case where a strong spring is used as the spring corresponding to the spring 7 in FIG. 1, and the dashed-dotted line shows the case where a weak spring is used.

In addition, as is clear from Fig. 4, in the conventional structure, in addition to the above-mentioned problems, the operating characteristics greatly differ depending on the strength of the spring (solid line and one-dot chain line) and the engine speed (h, Ω). For this reason, there is also the problem that low-speed valves with the same specifications cannot be used for various purposes.

[Effects of the Invention] As explained above, according to the present invention, the hydraulic pressure control characteristic during trolling operation is determined by
5) has been devised to obtain the above-mentioned characteristics shown in Fig. 3, so that the propeller rotation can be maintained over a wide lever angle range without being substantially affected by the strength of the spring 7 or the engine speed. This makes it possible to finely control the propeller rotation speed during trolling operation.

[Another Embodiment] In the structure shown in FIG. 2, the boundary 35 or the intermediate point 35A are used as boundaries, and the lines extend at different angles. The inclination angle of the boundary 35 with respect to the circumferential direction may be continuously changed over substantially the entire length of the boundary 35.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the embodiment of the present invention, Fig. 2 is a developed view of the spool outer circumference of Fig. 1, Fig. 3 is a graph of control characteristics of the embodiment of the invention, and Fig. 4 is a graph of control characteristics of the conventional structure. , FIG. 5 is a diagram corresponding to FIG. 2 of another embodiment.

Claims (1)

[Claims] A main hydraulic circuit extending from the hydraulic inlet to the hydraulic outlet, a main drain circuit connecting the main hydraulic circuit to the main drain outlet, a first spool controlling the opening degree of the main drain circuit, and a first spool having one end connected to the first spool. a compression spring that biases the spool in the direction of decreasing the opening degree; a second spool connected to the other end of the compression spring; and a control that faces the second spool and applies hydraulic pressure to the spool in the direction of decreasing the opening degree. a communication circuit connecting the control room and the above-mentioned main hydraulic inlet, a control circuit that can connect the control room to the control drain outlet in a manner that allows the opening degree to be adjusted freely; and an operating mechanism for rotating the second spool by rotating the second spool, the control circuit comprising a groove provided on the outer periphery of the second spool, and a control circuit located in the second spool in the opening decreasing direction with respect to the groove. a land portion capable of closing the control drain outlet, the boundary between the land portion and the groove being inclined with respect to the direction of rotation of the second spool and a direction parallel to the center line; When the rotation angle of the spool is small, the inclination angle of the front half of the boundary adjacent to the control drain outlet with respect to the rotation direction is determined by the second
A low-speed valve for a clutch hydraulic control device, characterized in that the angle of inclination of the latter half of the boundary adjacent to the control drain outlet is greater than the angle of inclination with respect to the rotational direction when the rotational angle of the spool is large.