2-position switching valve

Abstract

The present invention provides a two-position control valve that can switch between two positions by energizing and de-energizing, and that can suppress power consumption. [Solution] The two-position switching valve of the present invention includes a drive unit that moves the spool 5 by supplying pilot air, a biasing unit 11 that elastically biases the spool 5 at all times, and a lock cam mechanism 10 that can selectively switch between a locked state in which the movement of the spool toward the first position is locked at the second position and an unlocked state in which the lock is released. The present invention can alternately switch between the locked state and the unlocked state by pulsed energization, and can be held in any switching position without energization.

Description

Technical Field

[0001] The present invention relates to a two-position switching valve capable of switching between two positions by energizing and de-energizing a drive unit.

Background Art

[0002] A conventional two-position switching valve, as disclosed in, for example, Patent Document 1, is configured to switch to and hold a first switching position by pilot fluid pressure output by continuing excitation of a solenoid on one end side of a spool. When the excitation of the solenoid is released, the spool is moved to and held at a second switching position by the biasing force of a return spring on the other end side. In such a conventional two-position switching valve, it is necessary to continue energizing the solenoid of the pilot valve in order to maintain the first switching position. For this reason, the conventional two-position switching valve has a problem in terms of energy saving because power consumption increases when the spool is continuously held at the first switching position.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Accordingly, a technical problem to be solved by the present invention is to provide a two-position switching valve capable of suppressing power consumption by a drive unit.

Means for Solving the Problems

[0005] To solve the aforementioned problems, the present invention provides a two-position switching valve having a spool valve section having a valve hole that penetrates in the axial direction and has a first end and a second end at both ends in the axial direction, a plurality of ports communicating with the valve hole, and a spool inserted into the valve hole so as to be movable in the axial direction, and the two-position switching valve is capable of switching the communication state between the plurality of ports by selectively holding the spool in a first position on the first end side and a second position on the second end side in the axial direction, wherein the two-position switching valve includes a pilot valve section that supplies pilot air when energized, a drive section that moves the spool to the second end side by supplying the pilot air, a biasing section that elastically biases the spool to the first end side at all times, and a lock cam mechanism that can selectively switch between a locked state that locks the movement of the spool toward the first position at the second position and an unlocked state that releases the lock. The lock cam mechanism comprises: a rotating part connected to the spool on its axis, movable in the axial direction and rotatable around the axis, with a plurality of driven projections projecting radially from its outer circumferential surface, wherein the plurality of driven projections are arranged in a row circumferentially at equal angular intervals around the axis and have a tracing surface at least one of the two ends in the axial direction; a lock cam part in which a plurality of switching cam parts, each having a switching cam surface that follows the tracing surface of the driven projection and a locking part that prevents the rotating part from moving in the axial direction, and a plurality of sliding groove parts into which the driven projection is movable in the axial direction, are alternately arranged circumferentially on the inner circumferential surface of the lock cam hole into which the rotating part is movably inserted in the axial direction; and a rotating cam part in which a plurality of rotating cams, each having a rotating cam surface that follows the tracing surface of the driven projection and rotates the rotating part around the axis, are arranged in an annular manner around the axis.The lock cam mechanism is characterized by the following switching operations, performed by pulsed current flow: a first operation in which current is supplied to the pilot valve portion to move the rotating portion and the spool toward the second end and the driven projection follows the rotating cam, thereby rotating the rotating portion by a certain angle around its axis; and a second operation in which current is not supplied to the pilot valve portion to move the rotating portion and the spool toward the first end at the biasing portion; and a second operation in which current is not supplied to the pilot valve portion to move the rotating portion and the spool toward the first end at the biasing portion. These operations are performed by pulsed current flow, thereby alternately switching between a locked state in which the driven projection of the rotating portion engages with the locking portion of the lock cam portion to hold the spool in the second position, and an unlocked state in which the driven projection of the rotating portion moves along the slide groove to hold the spool in the first position.

[0006] In the present invention, the switching cam portion has a pair of guide surfaces extending in the axial direction and forming the side walls of the slide groove portion, and the end faces arranged at both ends in the axial direction, the end face at the second end having a first switching cam surface inclined with respect to the axis in a plan view, a second switching cam surface inclined in the same direction as the first switching cam surface, and a locking portion between the first switching cam surface and the second switching cam surface for engaging the driven projection, wherein the first switching cam surface drives the driven projection to the locking portion, and the second switching cam surface drives the driven projection to the slide groove portion.

[0007] Furthermore, in the present invention, it is preferable that the rotating cam surface is an inclined surface that is inclined with respect to the axis in a plan view. Moreover, it is preferable that the driven projection has a pair of sliding surfaces that are parallel to the axial direction and have different lengths, and a pair of end surfaces that connect the axial ends of the sliding surfaces to each other, and that the tracing surface has an inclined surface that is parallel to the first switching cam surface and the rotating cam surface.

[0008] Furthermore, it is preferable that the first switching cam surface and the rotating cam surface have an acute angle of inclination with respect to the axis in a plan view.

[0009] Furthermore, in the present invention, it is preferable that the slide grooves are arranged around the axis at equal angular intervals, the same as the driven projections of the rotating portion, and the rotating cams are arranged around the axis at equal angular intervals, half the interval of the driven projections of the rotating portion.

[0010] Furthermore, according to a specific embodiment of the present invention, in the two-position switching valve, the drive unit is located on the first end side of the spool valve unit, the lock cam unit is located on the second end side of the spool valve unit, the biasing unit is located on the second end side of the lock cam unit, the biasing unit has the rotating cam unit disposed at its first end, the plurality of driven projections of the rotating unit have the following surfaces at both ends in the axial direction, the following surface on the first end side follows the switching cam surface during the second operation, and the following surface on the second end side follows the rotating cam during the first operation. In this case, the spool has a neck portion and a head portion that is larger in diameter than the neck portion, extending coaxially from the end on the second end side, and the rotating portion is cylindrical with a lid portion on the first end side, and has a notch portion formed from a part of the outer circumferential surface on the first end side to the axial center portion of the lid portion, and it is desirable that the spool and the rotating portion are locked and connected in the axial direction by inserting the head portion of the spool into the rotating portion through the notch portion.

[0011] Furthermore, according to another embodiment of the present invention, the biasing portion is located on the second end side of the spool valve portion, the lock cam portion is located on the first end side of the spool valve portion, and the drive portion is located on the first end side of the lock cam portion, and has a push portion inserted into the lock cam hole so as to be immobile around the axis and movable in the axial direction, the rotating cam portion is formed on the end face of the second end side of the push portion, and the plurality of driven projections have the tracing surface on the first end side of both ends in the axial direction, and the tracing surface may follow the switching cam surface during the second operation and follow the rotating cam surface during the first operation.

[0012] Furthermore, it is preferable that the push portion is formed in a cylindrical shape and has a sliding projection on its outer surface that slides against the sliding groove of the lock cam portion.

[0013] Furthermore, it is also desirable that the spool has a cylindrical connecting portion extending coaxially from the end on the first end side, the rotating portion has a cylindrical large-diameter portion and a small-diameter portion on the first end side of the large-diameter portion, the driven projection is formed spanning the large-diameter portion and the small-diameter portion, the connecting portion of the spool is rotatably inserted into the large-diameter portion of the rotating portion from the first end side, and the small-diameter portion of the rotating portion is rotatably and reciprocally inserted into the push portion from the second end side.

[0014] Furthermore, in the present invention, the biasing portion may be a coil spring and / or an air spring. It is also preferable that the two-position control valve has an indicator that displays the switching position of the two-position control valve.

[0015] Furthermore, in the present invention, it is preferable that the valve casing having the spool valve portion inside and the lock cam body having the lock cam portion inside and being formed separately, and that the valve casing and the lock cam body are connected to each other in the axial direction. [Effects of the Invention]

[0016] According to the two-position switching valve of the present invention, by providing a lock cam mechanism, the two positions can be alternately switched by repeatedly applying and removing pulsed current to the drive unit, and both positions can be maintained in a non-powered state. Therefore, the present invention has the effect of suppressing power consumption compared to conventional valves and improving energy-saving performance. [Brief explanation of the drawing]

[0017] [Figure 1] This is a front view of a two-position switching valve representing a first embodiment of the present invention. [Figure 2] Figure 1 is a plan view of the switching valve. [Figure 3] This is a cross-sectional view of the switching valve taken along the line III-III in Fig. 2, where the upper and lower parts of the alternate long and short dash line respectively indicate the first position and the second position. [Figure 4] This is an exploded view showing the constituent elements of the lock cam mechanism. [Figure 5] This is a front view of the rotating part 7 in Fig. 4. [Figure 6] This is a left side view of the rotating part 7 in Fig. 5. [Figure 7] This is a cross-sectional view showing the connection structure of the spool 5, the rotating part and the return air piston in Fig. 4. [Figure 8] This is a left side view of the lock cam part in Fig. 4. [Figure 9] This is a cross-sectional view of the lock cam part in Fig. 8 taken along the line IX-IX and an enlarged view of the switching cam part 81. [Figure 10] This is a front view of the biasing part body in Fig. 1 and an enlarged view of the rotating cam part. [Figure 11] This is a left side view of the biasing part body in Fig. 10. [Figure 12] This is a cross-sectional view of the biasing part body in Fig. 11 taken along the line XII-XII. [Figure 13] This is a diagram showing the unlocked state (A) and the locked state (E) of the lock cam mechanism in the XIII-XIII cross-section of Fig. 2. [Figure 14] This is a diagram showing the transition steps from the unlocked state (A) to the locked state (E) in Fig. 13. [Figure 15] This is a diagram showing the transition steps from the locked state (E) to the unlocked state (A) in Fig. 13. [Figure 16] This is a plan development view of the lock cam mechanism 10, which is a schematic diagram for explaining the transition steps to the locked state (A) and the unlocked state (E) in Fig. 13. [Figure 17] This is a front view of the two-position switching valve representing the second embodiment of the present invention. [Figure 18] This is a plan view of the switching valve in Fig. 17. [Figure 19]Figure 18 is a cross-sectional view of the switching valve as seen from the XIX-XIX arrow, with the dashed lines above and below indicating the first and second positions, respectively. [Figure 20] This is an exploded view showing the components of the lock cam mechanism. [Figure 21] Figure 20 is a front view of the rotating part. [Figure 22] This is a right side view of the rotating part shown in Figure 21. [Figure 23] Figure 20 is a left side view of the lock cam section. [Figure 24] Figure 23 is a cross-sectional view of the lock cam portion taken along the line XXIV-XXIV. [Figure 25] Figure 20 shows a front view of the push mechanism and an enlarged view of the rotating cam. [Figure 26] Figure 25 is a right side view of the push section. [Figure 27] Figure 25 is a perspective view of the push button. [Figure 28] Figure 20 is a cross-sectional view showing the connection structure between the spool, the rotating part, and the pushing part. [Figure 29] This is a cross-sectional view of the lock cam portion at the first position, as seen from the arrow XXIX-XXIX in Figure 17. [Figure 30] This is a cross-sectional view of the indicator at the first position, as seen from the arrow XXX-XXX in Figure 29. [Figure 31] This is the lock cam portion at the second position in the cross-sectional view of Figure 29. [Figure 32] This is a cross-sectional view of the indicator at the second position, as seen from the arrow XXXII-XXXII in Figure 31. [Figure 33] This figure shows the unlocked state (A) and the locked state (D) of the lock cam mechanism in the XXXIII-XXXIII cross-section of Figure 18. [Figure 34] This diagram shows the transition steps from the unlocked state (A) to the locked state (D) in Figure 33. [Figure 35] This diagram shows the transition steps from the locked state (D) to the unlocked state (A) in Figure 33. [Figure 36]This is a plan view of a lock cam mechanism, illustrating the transition steps from the unlocked state (A) to the locked state (D). [Figure 37] This is a schematic diagram showing a plan view of a lock cam mechanism, illustrating the transition steps from the locked state (D) to the unlocked state (A). [Modes for carrying out the invention]

[0018] Figures 1-37 show two embodiments of the two-position switching valve according to the present invention. In this specification, the direction of the spool's central axis is referred to as the axial direction. Furthermore, in the axial direction, the end in the direction in which the spool moves due to the energization of the pilot valve is referred to as the second end 1b. The end opposite to the second end 1b, i.e., the end in the direction in which the spool moves due to the biasing part when no energy is supplied, is referred to as the first end 1a. The two-position switching valve of the present invention may also be simply referred to as a switching valve. In the following description, when terms relating to the up, down, left, and right directions are used, they are for convenience to indicate directions on the drawings and do not limit the actual arrangement.

[0019] (First Embodiment) Figures 1-16 show a preferred first embodiment of the two-position switching valve of the present invention. The switching valve 100 will be described below with reference to Figure 1-3.

[0020] As shown in Figures 1 and 2, the switching valve 100 is constructed by connecting a pilot valve section 17, an drive unit body 13, a valve casing 14, a lock cam body 18, and a biasing unit body 12 in the order from the first end 1a to the second end 1b. In the external shape of the switching valve 100, the valve casing 14, the lock cam body 18, and the biasing unit body 12 have equal height in the vertical direction, as shown in Figure 1, and equal thickness, as shown in Figure 2. Each body is formed as a roughly rectangular parallelepiped and is integrally connected. The lock cam body 18 is formed separately and is interconnected with the valve casing 14 in the axial direction. This switching valve can be constructed by relatively simple design modifications while utilizing the configuration of conventional switching valves.

[0021] As shown in Figure 2, the valve casing 14 has fixing screw holes 41 for fixing to a manifold located at the lower part (not shown). The valve casing 14 also has recesses 42 that align with the protrusions of the fixing screw holes of other switching valves, allowing multiple switching valves to be connected. The pilot valve section 17 supplies pilot air when power is supplied from the power supply unit and exhausts pilot air when power is not supplied.

[0022] Figure 3 is a cross-sectional view of the switching valve 100. The upper part of the dashed line indicates the first position (unlocked state) of the switching valve, and the lower part indicates the second position (locked state) of the switching valve. As shown in Figure 3, the valve casing 14 has a spool valve section 4 inside, which includes a valve hole 2 that penetrates in the axial direction L, five ports 3 (EB, B, P, A, EA) that communicate with the valve hole 2, and a spool 5 that is axially movable inserted into the valve hole 2.

[0023] The drive unit body 13 has a drive unit 6 inside, which consists of a drive cylinder 6a and a drive piston 6b. The drive piston 6b moves the spool 5 toward the second end 1b side by supplying pilot air from the pilot valve unit 17.

[0024] As shown in the lower part of Figure 3, when power is applied, pilot air is supplied from the pilot valve section 17, and the drive piston 6b moves the spool 5 toward the second end 1b. In this invention, as described above, the end of the main switching valve 100 in the direction in which the spool 5 moves when power is applied is called the second end 1b. The direction opposite to the second end 1b is called the first end 1a. Therefore, as shown by the arrows in Figure 3, in this embodiment, the biasing section body 12 side (right side) is the second end 1b side, and the drive section body 13 side is the first end 1a side (left side). The drive section 6 is located toward the first end 1a side of the spool valve section 4. The lock cam mechanism 10 having the lock cam section 8 is located toward the second end 1b side of the spool valve section 4, and the biasing section 11 is located toward the second end 1b side of the lock cam mechanism 10.

[0025] The biasing body 12 has a biasing section 11 inside that elastically biases the spool 5 toward the first end 1a at all times. In this embodiment, the biasing section 11 is composed of a return air spring 11a consisting of a return air cylinder 11c and a return air piston 11d. The biasing body 12 has a communication passage 121 formed therein for the return air cylinder 11c to constantly receive pilot pressure, and the return air spring 11a elastically biases the spool 5 toward the first end 1a at all times. Here, the cross-sectional area of ​​the drive piston 6b in the drive body 13 is formed to be larger than the cross-sectional area of ​​the return air piston 11d in the return air spring 11a. Therefore, when power is supplied and pilot pressure is applied to both pistons, the difference in pressure-receiving area causes the drive piston 6b to move the spool 5 toward the second end 1b at all times. In this embodiment, the biasing section 11 is made of an air spring, but it may be made of other elastic materials. Specifically, the biasing section 11 can be made of any material that constantly provides elastic bias. For example, it may be a mechanical spring such as a coil spring. Alternatively, the biasing section 11 may be made of a combination of an air spring and a coil spring.

[0026] In Figure 3, the upper and lower diagrams show the positions of the spool 5 in the two-position switching valve 100. The upper diagram shows the case where the spool 5 is in the first position on the first end 1a side. The first position is the position where the spool 5 is moved towards the first end 1a side by the biasing unit 11, and the P port and A port are in communication. Furthermore, the diagram below shows the case where the spool 5 is in the second position, which is on the second end 1b side of the first position. The second position is the position where the spool 5 moves toward the second end 1b side, and the P port and the B port are connected. The switching valve 100 of this embodiment selectively holds the spool 5 in a first position P1 on the axial first end 1a side and a second position P2 on the second end 1b side, thereby enabling the switching of the communication state of multiple ports 3 as described above.

[0027] Furthermore, in Figure 3, a lock cam body 18 is disposed between the valve casing 14 and the biasing body 12. The lock cam body 18 has a lock cam mechanism 10 inside for selectively switching between the two positions of the main switching valve. The lock cam mechanism 10 will be described with reference to Figure 4-13.

[0028] (Lock cam mechanism 10) Figure 4 shows an exploded perspective view of the lock cam mechanism 10. The lock cam mechanism 10 is capable of selectively switching between a locked state, which locks the movement of the spool 5 toward the first position at the second position shown in the lower diagram of Figure 3, and an unlocked state, which releases the lock. The lock cam mechanism 10 consists of a rotating part 7, a lock cam part 8 formed on the lock cam body 18, and a rotating cam part 9.

[0029] The rotating part 7 is formed in a cylindrical shape, and its first end 1a is connected to the second end 1b of the spool 5 on its axis so as to be movable in the axial direction and rotatable around the axis. In addition, a plurality of driven protrusions 71 are provided radially on the outer circumferential surface of the rotating part 7. Specifically, on the outer circumferential surface of the rotating part 7, the plurality of driven protrusions 71 are arranged in a line in the circumferential direction at equal angular intervals around the axis.

[0030] The lock cam body 18 has a lock cam hole 83 into which the rotating part 7 is inserted so as to be movable in the axial direction L. The inner circumferential surface of the lock cam hole 83 has a lock cam portion 8 in which the driven projection 71 locks or unlocks the axial movement.

[0031] In this embodiment, the rotating cam section 9 is provided on the biasing body 12 and is formed by arranging a plurality of rotating cams 91 in an annular shape around an axis. With this configuration, when power is applied, the rotating part 7 moves axially towards the second end 1b within the lock cam hole 83, contacts the rotating cam part 9, and rotates by a certain angle in a certain direction. Next, when power is removed, the rotating part 7 moves towards the first end 1a due to the biasing part 11. Further details will be described later.

[0032] The return air piston 11d biases the spool 5 and the rotating part 7 toward the first end 1a when the power is not supplied. The retaining spring 19 will be described later.

[0033] Next, the individual components that make up the lock cam mechanism 10 will be described in detail. (Rotating part 7) Figure 5-6 shows the structure of the rotating part 7 of this embodiment. As shown in Figure 5, the rotating part 7 of this embodiment has a cylindrical main body 74, and the main body 74 has a cover 73 that covers the opening on the first end 1a side. The main body 74 also has a plurality of driven projections 71 that protrude radially from the outer surface near the axial center, and the driven projections 71 are arranged in a single row in the circumferential direction on the outer surface.

[0034] An enlarged view of Figure 5 shows the shape of the driven projection 71 in detail. The driven projection 71 has a pair of opposing sliding surfaces that are parallel to the axial direction and have different lengths. In this embodiment, the driven projection 71 has a first sliding surface 71c that is parallel to the axial direction L, and a second sliding surface 71d that is longer in the axial direction than the first sliding surface 71c. The driven projection 71 also has a pair of end surfaces that connect the axial ends of the first sliding surface 71c and the second sliding surface 71d. In this embodiment, the cross-section along the outer circumferential surface of the driven projection 71 is an isosceles trapezoid. The axial end surfaces of the driven projection 71 are inclined surfaces that are inclined with respect to the axis in a plan view, and in this embodiment, the driven projection 71 has tracing surfaces on both end surfaces. Specifically, the driven projection 71 has a first tracing surface 71a on the second end 1b side and a second tracing surface 71b on the first end 1a side. The first tracing surface 71a and the second tracing surface 71b have inclined surfaces parallel to the first switching cam surface 81a and the rotating cam surface 91a, which will be described later. In this embodiment, these inclined surfaces have an inclination angle of 60 degrees with respect to the axis in a plan view. The first tracing surface 71a is positioned opposite the rotating cam 91 of the rotating cam section 9 located on the second end 1b side. The second tracing surface 71b is positioned opposite the lock cam section 8 located on the first end 1a side.

[0035] As shown in Figure 6, the multiple driven protrusions 71 are arranged circumferentially on the outer surface of the main body 74 at equal angular intervals around the axis. The number of driven protrusions 71 can be multiple, but two or three or more are preferred. In this embodiment, eight driven protrusions 71 are arranged on the outer surface of the main body 74 at equal angular intervals of 45 degrees around the axis.

[0036] The connection structure between the rotating part 7 and the spool 5 will be explained with reference to Figures 5-7. As shown in Figures 5-6, the main body 74 and cover 73 of the rotating part 7 have notches 72 into which the end of the spool 5 on the second end 1b side can be inserted from a direction perpendicular to the axial direction. The notches 72 are also provided with positioning projections 72a for positioning the spool 5 coaxially with the rotating part 7.

[0037] As shown in Figure 7, the end of the spool 5 on the second end 1b side has a neck portion 51 smaller than the diameter of the spool 5, and a head portion 52 larger in diameter than the neck portion 51 and smaller than the diameter of the spool 5, both extending along the axis of the spool 5. Furthermore, the end of the head portion 52 on the first end 1a side has a spring receiving portion 53 formed thereon, which has a larger outer diameter than the head portion 52. With this connecting structure, the rotating portion 7 is connected to the spool 5 on its axis so that it can move in the axial direction and rotate freely around the axis.

[0038] As shown in Figure 7, the rod of the return air piston 11d and the retaining spring 19 are inserted into the rotating part hole 78 of the rotating part 7 from the second end 1b side. The spool 5 has a spool packing 54. The spring receiving part 53 of the spool 5 is for supporting the end of the coil-shaped retaining spring 19. Here, the retaining spring 19 presses the return air piston 11d and the spool 5 to both ends during transport, preventing the spool 5 from rattling due to vibrations during transport. In addition, when compressed air is exhausted due to an emergency stop or the like while the valve is in use, the retaining spring 19 maintains the position of the spool 5 against the pressure difference of the exhaust air and external shocks. This prevents the valve from malfunctioning when compressed air is resupplied during recovery. When this switching valve is in use, the elastic modulus of the retaining spring 19 is set so that it is always compressed by the return air spring 11a which receives pilot pressure. As a result, the retaining spring 19 does not affect the operation of the switching valve 100 when the switching valve 100 is in use.

[0039] (Lock cam section 8) Figure 8-9 shows the structure of the lock cam body 18 and the lock cam portion 8 of this embodiment. Figure 8 is a left side view of the lock cam body 18 in Figure 1, and Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8.

[0040] The lock cam body 18 has a lock cam hole 83 that penetrates axially, allowing the rotating part 7 to move in the axial direction. The lock cam hole 83 is formed to be coaxial with the spool 5 and the rotating part 7.

[0041] The lock cam portion 8 is formed on the inner circumferential surface of the lock cam hole 83. Specifically, the lock cam portion 8 is formed projecting from the inner circumferential surface in the circumferential direction of the inner circumferential surface of the lock cam hole 83. The lock cam portion 8 has a plurality of switching cam portions 81, each having a switching cam surface (first switching cam surface 81a, second switching cam surface) that drives the second tracing surface 71b of the rotating portion 7, and a locking portion 81c that prevents the rotating portion 7 from moving toward the first end 1a in the axial direction. In addition, a plurality of slide groove portions 82 are formed between adjacent plurality of switching cam portions 81. The plurality of switching cam portions 81 and the plurality of slide groove portions 82 are arranged alternately in the circumferential direction of the inner circumferential surface of the lock cam hole 83. The driven projection 71 of the rotating portion 7 slides in the axial direction within the slide groove portion 82. Therefore, as shown in Figures 6 and 8, the multiple slide grooves 82 are provided at eight equal angular intervals of 45 degrees around the axis, similar to the driven projections 71. Similarly, eight switching cams 81 are also provided at equal angular intervals, similar to the slide grooves 82.

[0042] The rotating part 7 is positioned to move axially within the lock cam hole 83. Therefore, the inner diameter of the slide groove portion 82 of the lock cam hole 83 is larger than the outer diameter of the driven projection 71 portion of the rotating part 7. Also, the inner diameter of the switching cam portion 81 of the lock cam hole 83 is larger than the outer diameter of the main body portion 74 of the rotating part 7. The projection 87 formed on the lock cam body 18 is used for alignment when connecting with the valve casing 14. The communication passage 88 is for guiding pilot pressure to the biasing body 12. The fixing hole 89 is a screw hole provided for integrally connecting and fixing the valve casing 14, the lock cam body 18, the biasing body 12, etc.

[0043] As shown in Figure 9, the switching cam portion 81 is formed within the lock cam hole 83, positioned closer to the first end 1a side than the midpoint in the axial direction. The enlarged view of Figure 9 shows the detailed structure of the switching cam portion 81 within the lock cam hole 83.

[0044] The switching cam section 81 has a pair of first guide surfaces 81e and second guide surfaces 81f that are parallel to each other in the axial direction and facing away from each other. Of the end faces located at both ends of the switching cam section 81 in the axial direction, the end face on the second end 1b side has a first switching cam surface 81a that is inclined with respect to the axis in a plan view, a second switching cam surface 81b that is inclined in the same direction as the first switching cam surface 81a, and a locking portion 81c that engages the driven projection 71 between the first switching cam surface 81a and the second switching cam surface 81b.

[0045] Specifically, the first switching cam surface 81a is formed at a 60-degree inclination angle with respect to the axis in a plan view, from the first starting point portion 81g to the locking portion 81c, and the second switching cam surface 81b is formed parallel to the first switching cam surface 81a. A locking portion 81c is formed between the first switching cam surface 81a and the second switching cam surface 81b to prevent the driven projection 71 of the rotating portion 7 from moving in the axial direction. The first switching cam surface 81a is formed from the first starting point portion 81g, which is located closest to the second end 1b in the axial direction, to the locking portion 81c, and a locking surface 81d is formed parallel to the first guide surface 81e and the second guide surface 81f, from the locking portion 81c to the second starting point portion 81h of the second switching cam surface 81b. Furthermore, the first switching cam surface 81a is formed to be longer than the second switching cam surface 81b. The first starting point portion 81g and the second starting point portion 81h are formed on the same circumference on the inner circumference of the lock cam hole 83. The second switching cam surface 81b, like the first switching cam surface 81a, is inclined at a 60-degree angle with respect to the axis to the second guide surface 81f. As a result, the driven projection 71 is driven to the locking portion 81c by the first switching cam surface 81a, and also driven to the slide groove portion 82 by the second switching cam surface 81b.

[0046] Furthermore, in the lock cam portion 8, eight locking portions 81c are formed at equal angular intervals of 45 degrees around the axis, similar to the driven projection 71. In addition, the angle of the inclined surfaces on the first switching cam surface 81a and the second switching cam surface 81b can be formed at an acute angle, and in this embodiment, it is formed at 60 degrees. As a result, the second tracing surface 71b of the driven projection 71 makes surface contact with the switching cam surfaces 81a and 81d, allowing it to move smoothly.

[0047] (Rotating cam section 9) Figure 10-12 shows the structure of the biasing body 12. Figure 10 is a front view of the biasing body 12 shown in Figure 1.

[0048] The rotating cam section 9 protrudes axially from the end face of one end of the biasing section body 12, and is formed by arranging a plurality of annular rotating cams 91 around the axis. In this embodiment, the rotating cam section 9 is formed annularly around the axis at the opening of the return air cylinder 11c of the biasing section 11.

[0049] Based on the enlarged view of Figure 10, the structure of the rotating cam section 9 will be explained in detail. The rotating cam portion 9 has an annular base portion 91e, and a plurality of rotating cams 91 are formed in a sawtooth pattern on the first end 1a side of the base portion 91e. The rotating cam 91 has a contact surface 91b formed parallel to the axial direction from the base point 91c of the base portion 91e, and a rotating cam surface 91a is formed from its apex 91d to the base point 91c of the adjacent rotating cam 91. The rotating cam surface 91a is formed as an acute-angled inclined surface with respect to the axis in a plan view, and in this embodiment, it is formed as an inclined surface that inclins toward the second end 1b at an angle of 60 degrees. In this embodiment, the inclination angle of the first tracing surface 71a of the driven projection 71 is set to the same angle as the rotating cam surface 91a, i.e., 60 degrees. As a result, the rotating cam surface 91a can make surface contact with the first tracing surface 71a of the driven projection 71 and be driven smoothly. Furthermore, the rotating cams 91 are provided at equal angular intervals of half the angle of the driven projections 71, i.e., at equal angular intervals of 22.5 degrees. Therefore, the number of rotating cams 91 is twice the number of driven projections 71 on the rotating part 7, and in this embodiment, 16 cams are formed.

[0050] As shown in Figures 11-12, the inner diameter of the rotating cam portion 9 is formed to be slightly larger than the inner diameter of the return air cylinder 11c of the biasing body 12. The outer diameter of the rotating cam portion 9 is formed to be smaller than the inner diameter of the lock cam hole 83 in Figure 9. As a result, when the biasing body 12 and the lock cam body 18 are connected, the rotating cam portion 9 is fitted into the lock cam hole 83 shown in Figure 9 from the second end 1b side. On the other hand, the inner diameter of the rotating cam portion 9 is set to be smaller than the outer diameter of the rotating portion 7 including the driven projection 71, in order for the rotating cam portion 9 to contact and drive the driven projection 71 of the rotating portion 7.

[0051] As described above, in this switching valve 100, the first tracing surface 71a and the second tracing surface 71b of the driven projection 71 in the rotating part 7, the first switching cam surface 81a and the second switching cam surface 81b in the switching cam part 81, and the rotating cam surface 91a of the rotating cam 91 in the rotating cam part 9 are all inclined surfaces with an inclination angle of 60 degrees with respect to the axis in a plan view. Preferably, this inclination angle is acute with respect to the axis in a plan view.

[0052] With this configuration, when the pilot valve section 17 is energized in a pulsed manner, the first tracing surface 71a of the driven projection 71 comes into contact with the rotating cam surface 91a and moves with it when the rotating section 7 moves furthest toward the second end 1b. As a result, the rotating section 7 rotates by a certain angle in a specific direction. Also, when the pilot valve section 17 is not energized, the biasing section 11 moves the rotating section 7 toward the first end 1a. In this state, the second tracing surface 71b of the driven projection 71 comes into contact with the switching cam surfaces 81a, 81b and moves with it. As a result, the rotating section 7 rotates by a certain angle in a specific direction. Furthermore, in this embodiment, in the lock cam mechanism 10, the lock cam portion 8 and the rotating cam portion 9 are fixedly formed relative to their respective bodies, while the rotating portion 7 is formed to be movable in the axial direction and rotatable around its axis.

[0053] (Operation of the lock cam mechanism 10 in the first embodiment) The operation of the lock cam mechanism 10 of this embodiment will be explained with reference to Figures 13-16. Figures 13-15 show the transition steps between the locked and unlocked states of the lock cam mechanism 10 in the XIII-XIII section of Figure 1.

[0054] Figure 13(A) shows the first position of the first end 1a of the switching valve 100, i.e., the unlocked state. Figure 13(E) shows the second position of the second end 1b, i.e., the locked state. Figure 16(a) is a plan view of the lock cam mechanism 10, and is a schematic diagram showing the transition steps from the unlocked state to the locked state.

[0055] The lock cam mechanism 10 performs a series of switching operations by pulsed current, which involves a first operation in which the rotating part 7 is rotated by a certain angle in the axial direction by energizing the pilot valve section 17, moving the rotating part 7 and the spool 5 toward the second end 1b, and causing the multiple driven projections 71 to follow the multiple rotating cams 91; and a second operation in which the rotating part 7 and the spool are moved toward the first end 1a by the biasing section 11 by de-energizing the pilot valve section 17. Through this series of switching operations of the lock cam mechanism 10, a locked state is alternately performed in which the driven projections 71 of the rotating part 7 engage with the switching cam section 81, holding the spool 5 in the second position, and an unlocked state in which the driven projections 71 of the rotating part 7 move along the slide groove section 82, holding the spool in the first position. The series of switching operations performed by the lock cam mechanism 10 will be described in detail below, based on Figures 13-16.

[0056] The transition from the unlocked state in Figure 13(A) to the locked state in Figure 13(E) is shown in Figures 14 and 16(a). Figure 16(a) is a plan view of the lock cam mechanism 10, and is a schematic diagram showing the transition steps from the unlocked state (A) to the locked state (D). State A: State A in Figures 13(A) and 16(a) shows that the pilot valve section 17 is not energized, and the spool 5 is held in the first position on the first end 1a side. The driven projection 71 of the rotating section 7 is located in the slide groove 82 of the lock cam section 8, indicating the unlocked state.

[0057] (First operation of the first time) Figures 14(B) and (C) below illustrate the first operation in this transition step. The first operation involves energizing the pilot valve section 17 to move the rotating section 7 and the spool 5 toward the second end 1b, and simultaneously causing the rotating section 7 to rotate by a certain angle in the axial direction by making the multiple driven protrusions 71 follow the multiple rotating cams 91. State B: As shown in State B of Figures 14(B) and 16(a), pulsed current is applied to move the drive piston 6b toward the second end 1b. As a result, the rotating part 7 moves toward the second end 1b together with the spool 5. State B shows the state in which the driven projection 71 of the rotating part 7 is in contact with the rotating cam part 9 of the biasing part body 12. State C: Next, State C in Figures 14(C) and 16(a) shows the state where the rotating part 7 has moved furthest toward the second end 1b due to the application of power (full stroke). The driven projection 71 drives the rotating cam surface 91a of the rotating cam part 9, causing the rotating part 7 to rotate by a certain angle in a specific direction.

[0058] (Second operation on the first attempt) Figures 14(D) and 13(E) below illustrate the second operation in this transition step. The second operation involves de-energizing the pilot valve section 17, thereby moving the rotating section 7 and the spool 5 toward the first end 1a side using the return air piston 11d. State D: As shown in State D of Figures 14(D) and 16(a), by de-energizing, the pilot air that was driving the drive piston 6b is exhausted, and the spool 5 and rotating part 7 move toward the first end 1a due to the elastic force of the return air spring 11a on the biasing part body 12 side. At this point, due to the rotation in the first operation, the driven projection 71 has moved from the position of the slide groove 82. Therefore, State D indicates a state in which the driven projection 71 is in contact with the first switching cam surface 81a of the switching cam part 81 of the lock cam part 8. State E: Next, as shown in State E of Figures 13(E) and 16(a), the driven projection 71 of the rotating part 7 slides on the first switching cam surface 81a of the switching cam part 81 and is locked by the locking part 81c of the switching cam part 81, resulting in a locked state.

[0059] In this way, the switching valve 100 switches from the first position (unlocked state) to the second position (locked state) with a single pulse of energization and de-energization. The spool 5 is then held in the second position in the de-energized state. As described above, the lock cam mechanism 10 performs a series of switching operations from the unlocked state (A) to the locked state (E) with a single pulse of current.

[0060] Next, the transition operation from the locked state in Figure 13(E) to the unlocked state in Figure 13(A) is shown in Figures 15 and 16(b). Figure 16(b) is a plan view of the lock cam mechanism 10, and is a schematic diagram showing the transition steps from the locked state (E) to the unlocked state (A). State E: State E in Figures 13(E) and 16(b) is a locked state in which the driven projection 71 of the rotating part 7 is engaged with the locking part 81c of the switching cam part 81.

[0061] (Second first operation) Figures 15(F) and 15(G) below illustrate the second first operation in this transition step. State F: Due to pulsed current application, the rotating part 7 moves toward the second end 1b side together with the spool 5, as shown in State F in Figures 15(F) and 16(b). State F is the state in which the driven projection 71 of the rotating part 7 is in contact with the rotating cam part 9 of the biasing part body 12. State G: State G in Figures 15(G) and 16(b) is the state in which the rotating part 7 has moved furthest toward the second end 1b due to the application of power, i.e., the full stroke state. Then, the driven projection 71 moves in accordance with the rotating cam surface 91a of the rotating cam part 9, causing the rotating part 7 to rotate by a certain angle.

[0062] (Second operation of the second time) Figures 15(H) and 13(A) below illustrate the second operation in this transition step. State H: As shown in State H of Figures 15(H) and 16(b), by de-energizing the pilot valve section 17, the air in the drive piston 6b is exhausted, and the spool 5 and rotating section 7 move toward the first end 1a due to the elastic force of the return air spring 11a on the biasing section body 12 side. At this point, due to the rotation in the first operation described above, the driven projection 71 of the rotating section 7 moves by a certain angle from the position of the locking portion 81c of the switching cam section 81. As a result, the driven projection 71 of the rotating section 7 comes into contact with the second switching cam surface 81b of the switching cam section 81 of the lock cam section 8. State A: As shown in State A of Figures 13(A) and 16(b), the driven projection 71 of the rotating part 7 is driven by the second switching cam surface 81b of the switching cam part 81 in the lock cam part 8, returns to the slide groove part 82, and the restriction on movement is released. In this way, the spool 5 is held in the first position in an unpowered state.

[0063] Thus, the switching valve 100 of the present invention can alternately switch between two positions by continuous operation of pulsed energization and de-energization, and both switching positions can be maintained in a de-energized state. This switching valve can be switched using only pulsed energization and can maintain its position in a de-energized state. For this reason, this switching valve can keep power consumption low, and since only a signal line for pulses is required, costs can be reduced.

[0064] (Second Embodiment) Figures 17-37 show a second embodiment of the two-position switching valve according to the present invention. Components with the same function as in the first embodiment are indicated by the same numbers. In this case, descriptions of the shape, structure, etc., of components with the same numbers are omitted as appropriate.

[0065] Figures 17 and 18 show the overall configuration of the switching valve 200. The switching valve 200 consists of a pilot valve section 17, a biasing section body 12, a valve casing 14, a lock cam body 18, and an drive section body 13.

[0066] The difference here from the first embodiment is that the arrangement of the biasing body 12 and the drive body 13 is reversed. As described above, in the present invention, in the axial direction, the end in the direction in which the spool 5 moves due to the energization of the pilot valve 17 is called the second end 1b, and the opposite end is called the first end 1a. Therefore, in this embodiment, in Figure 17, the end of the pilot valve 17 is the second end 1b, and the end of the drive body 13 is the first end 1a.

[0067] Furthermore, in this embodiment, the lock cam body 18 is provided with an indicator 16 that displays the switching position of the switching valve.

[0068] Figure 19 is a cross-sectional view of the switching valve 200. The upper part of the dashed line indicates the first position (unlocked state) of the switching valve, and the lower part indicates the second position (locked state) of the switching valve.

[0069] The diagram above the dashed line in Figure 19 shows the unlocked state where the spool 5 is in the first position and the movement restriction of the rotating part 7 is released. The first position is the position where the spool 5 has moved toward the first end 1a and the P port and A port are in communication. The diagram below the dashed line shows the locked state where the spool 5 is in the second position and the movement of the rotating part 7 is restricted. The second position is the position where the spool 5 has moved toward the second end 1b and the P port and B port are in communication. In this embodiment, the biasing part 11 arranged in the biasing part body 12 is composed of a return coil spring 11b for constantly elastically biasing the spool 5 toward the first end 1a. The drive part 6 at the first end 1a is driven by the supply and exhaust of pilot air by the pilot valve part 17 at the second end 1b, as in the first embodiment.

[0070] (Lock cam mechanism 10) Figure 20 shows an exploded perspective view of the lock cam mechanism 10 in this embodiment. The lock cam mechanism 10 consists of a rotating part 7 connected to the spool 5, a rotating cam part 9 provided on the push part 15, and a lock cam part 8 provided in the lock cam hole 83 of the lock cam body 18. In this embodiment, the rotating cam part 9 is provided on the push part 15, which is different from the first embodiment. The drive unit body 13 at the first end 1a is provided with a drive piston 6b as a drive unit 6 that presses the push part 15. The lock cam body 18 is also provided with an indicator 16 that displays the switching position of the switching valve 200. The individual components of the lock cam mechanism 10 in this embodiment will be described below.

[0071] (Rotating part 7) Figures 21 and 22 show the structure of the rotating part 7 in this embodiment. As shown in Figure 21, the rotating part 7 is cylindrical and has a large diameter portion 75 on the second end 1b side and a small diameter portion 76 on the first end 1b side, and the two are formed continuously via the shoulder portion 77 of the large diameter portion 75. The rotating part 7 is penetrated in the axial direction, and the lengths of the large diameter portion 75 and the small diameter portion 76 are formed to be approximately the same length. On the outer circumferential surface of the rotating part 7, the driven projections 71 are provided in a line at equal angular intervals in the circumferential direction, spanning both the large diameter portion 75 and the small diameter portion 76, from the shoulder portion 77 of the large diameter portion 75 to the small diameter portion 76.

[0072] Each driven projection 71, as shown in the enlarged view of Figure 21, has a first sliding surface 71c parallel to the axial direction and a second sliding surface 71d that is longer than the first sliding surface 71c, and its cross-section along the outer circumference is a right-angled trapezoid. Of the two end faces of the driven projection 71, the first end side 1b has a first tracing surface 71a formed thereon, which has an inclination angle of 60 degrees with respect to the axis in a plan view. In this embodiment, the tracing surface of the driven projection 71 is only the first tracing surface 71a on the first end side 1a.

[0073] Furthermore, as shown in Figure 22, in this embodiment, the multiple driven protrusions 71 of the rotating part 7 are arranged in groups of six at equal angular intervals of 60 degrees around the axis.

[0074] (Lock cam section 8) Figures 23 and 24 show the structure of the lock cam body 18 and the lock cam portion 8. Figure 23 is a left side view of the lock cam portion 8 in Figure 17, and Figure 24 is a cross-sectional view taken along the line XXIV-XXIV in Figure 23. The lock cam body 18 is positioned between the valve casing 14 and the drive unit body 13 and has a rectangular parallelepiped shape. The valve casing 14 and the lock cam body 18 are interconnected in the axial direction. Also, on the inner circumferential surface of the lock cam hole 83 of the lock cam body 18, a switching cam portion 81 having a certain thickness and a slide groove portion 82 between adjacent switching cam portions 81 are provided, similar to the first embodiment. In this embodiment, the slide groove portion 82 is provided at six equal angular intervals of 60 degrees around the axis, similar to the driven projection 71 of the rotating portion 7.

[0075] Furthermore, as shown in Figure 24, the switching cam portion 81 has a locking portion 81c formed on the second end 1b side for engaging the driven projection 71. The first switching cam surface 81a, the second switching cam surface 81b, the locking portion 81c, and the locking surface 81d are formed on the second end 1b side of the switching cam portion 81. The configuration and function of each are the same as in the first embodiment, so their explanation will be omitted.

[0076] Here, the angle of the inclination of the first switching cam surface 81a and the second switching cam surface 81b with respect to the axis in a plan view is formed to be the same angle as the angle of the first tracing surface 71a of the driven projection 71 in order to ensure smooth movement by surface contact with the first tracing surface 71a of the driven projection 71. Therefore, in this embodiment as well, it is formed at 60 degrees. Furthermore, the first starting point portion 81g of the first switching cam surface 81a and the second starting point portion 81h of the second switching cam surface 81b are formed at equal angular intervals of half the distance between the driven projections 71 of the rotating portion 7, i.e., at intervals of 30 degrees around the axis. In addition, the starting points 81h of adjacent switching cam portions 81 are formed at intervals of 60 degrees around the central angle.

[0077] (Rotating cam section 9) Figure 25-27 shows the push portion 15 having a rotating cam portion 9 of the lock cam mechanism 10. In the first embodiment, the rotating cam portion 9 is formed on the biasing body 12, but in this embodiment, it is formed on the movable push portion 15. The push portion 15 is cylindrical, and on its outer circumferential surface, in the axial direction, there are multiple sliding protrusions 151 that slide in the sliding groove portion 82 of the lock cam portion 8, with the same number of protrusions at equal angular intervals as the sliding groove portion 82. In this embodiment, there are six sliding protrusions 151 at equal angular intervals of 60 degrees around the axis. Also, as shown in Figures 26 and 27, the push portion 15 has a cover portion 154 with a hole in the center at the end face of the first end 1a, and the second end 1b is open to form a push portion hole 152. An annular rotating cam portion 9 is formed projecting from the opening of the push portion 15 towards the second end 1b around the axis.

[0078] As shown in the enlarged view of Figure 25, the rotating cam portion 9 has an annular base portion 91e, and a plurality of rotating cams 91 are provided on the second end 1b side of the base portion 91e. In this embodiment, the cross-section of each rotating cam 91 is an isosceles triangle with a vertex angle of 120 degrees, with the line connecting adjacent base points 91c as the base and the vertex portion 91d as the vertex. The rotating cam surface 91a is an inclined surface at 60 degrees with respect to the axis, and since it has the same inclination angle as the first tracing surface 71a of the driven projection 71, it makes surface contact with the rotating cam surface 91a and moves smoothly. The other inclined surface of the rotating cam 91 is the contact surface 91b. The driven projection 71 slides along the rotating cam surface 91a and stops moving when it comes into contact with the contact surface 91b at the base point portion 91c.

[0079] The number of rotating cams 91 is twice the number of driven projections 71 on the rotating part 7 and the sliding grooves 82 on the locking cam part 8. Furthermore, the spacing between the rotating cams 91 is half the spacing between the driven projections 71 on the rotating part 7, resulting in equal angular intervals. Therefore, in this embodiment, the rotating cam part 9 has 12 rotating cams 91, arranged at equal angular intervals of 30 degrees around the axis.

[0080] In this embodiment, as shown in Figures 25-27, one of the six sliding protrusions 151 of the push section 15 has an indicator slider cam 153 extending from it, which converts the axial movement of the push section 15 into the vertical movement of the indicator 16, which will be described later. The indicator 16 will be described later.

[0081] Figure 28 shows the axial connection structure of the spool 5, the rotating part 7, and the push part 15. In this embodiment, a cylindrical connecting portion 55 extends coaxially from the end of the spool 5 on the first end 1a side. The connecting portion 55 of the spool 5 is inserted into the rotating portion hole 78 of the large diameter portion 75 of the rotating portion 7. The small diameter portion 76 of the rotating portion 7 is inserted into the push portion hole 152 of the push portion 15 so as to be rotatable around its axis and movable in the axial direction. The driven projection 71 of the rotating portion 7 contacts and is driven by the rotating cam portion 9 of the push portion 15 when it is in the position indicated by the dashed line. Therefore, the inner diameter of the large diameter portion 75 of the rotating portion 7 is formed to be larger than the outer diameter of the connecting portion 55 of the spool 5. Also, the outer diameter of the small diameter portion 76 of the rotating portion 7 is formed to be smaller than the inner diameter of the push portion hole 152 of the push portion 15.

[0082] Here, the spool 5 is elastically biased at all times toward the first end 1a by the return coil spring 11b, and the drive piston 6b is driven toward the second end 1b. Therefore, the rotating member 7 is connected so that it can move in the axial direction and rotate freely around the axis simply by inserting the connecting portion 55 of the spool 5 into the large diameter portion 75 of the rotating part 7.

[0083] (Indicator 16) This switching valve 200 is driven only by pulsed energization. Therefore, unlike conventional switching valves, it is not possible to confirm the switching position based on whether it is energized or not. To address this issue, this switching valve 200 is equipped with an indicator 16 to display externally which switching position it is in. Figures 29-30 show the state of the indicator 16 when the switching valve 200 is in the first position on the first end 1a side. The indicator 16 in this embodiment is rod-shaped and has a tip portion 162 at one end that extends in and out of the outer surface of the lock cam body 18, and an annular sealing portion 163 on the other end of the tip portion 162. An indicator slide groove 161 is formed on the other end of the indicator 16, which engages with and is driven by the indicator slider cam 153 of the push portion 15. The indicator slider cam 153 of the push section 15 is formed on one of the slide protrusions 151 and is configured to change in height in a direction perpendicular to the axial direction of the push section 15. With this structure, axial movement in the push section 15 is converted into displacement in the indicator 16 in a direction perpendicular to the axial direction.

[0084] In this embodiment, the indicator 16 moves in accordance with the indicator slider cam 153 of the push section 15 and protrudes from the upper surface of the lock cam body 18, thereby indicating to the outside that the switching valve is in the first position. Similarly, in Figures 31-32, the indicator 16 moves in accordance with the indicator slider cam 153 of the push section 15 and descends from the upper surface of the lock cam body 18, thereby indicating to the outside that the switching valve is in the second position. As a result, the switching position of the switching valve 200 can be visually confirmed from the outside. In this embodiment, an example of a mechanically driven indicator is shown, but indicators may also be configured using signals from various sensors. For example, they may be configured using a pressure sensor on an output port or a position sensor using a magnet or the like.

[0085] (Operation of the lock cam mechanism 10 in the second embodiment) The operation of the lock cam mechanism 10 in this embodiment will be explained with reference to Figures 33-37. In this embodiment, the rotating part 7 and the push part 15 having the rotating cam part 9 of the lock cam mechanism 10 are movable in the axial direction relative to the lock cam part 8.

[0086] Figures 33-35 show the transition steps between the locked and unlocked states in the XXXIII-XXXIII section of Figure 18. Figure 33(A) shows the first position of the first end 1a of the switching valve, i.e., the unlocked state. Figure 33(D) shows the second position of the second end 1b, i.e., the locked state. Figures 36 and 37 are plan views of the lock cam mechanism 10, schematic diagrams showing the transition steps between the unlocked state (A) and the locked state (D). The following describes in detail the series of switching operations performed by the lock cam mechanism 10 of this embodiment, based on Figures 33 to 37.

[0087] The transition from the unlocked state in Figure 33(A) to the locked state in Figure 33(E) is shown in Figures 34 and 36. State A: State A in Figures 33(A) and 36(a) shows that the pilot valve section 17 is not energized, and the spool 5 is held in the first position on the first end 1a side. The driven projection 71 of the rotating section 7 is located in the slide groove 82 of the lock cam section 8, indicating the unlocked state.

[0088] (First operation of the first time) Figures 34(B) and 34(C) below illustrate the first operation in this embodiment. State B: As shown in State B of Figures 34(B) and 36(b), the drive piston 6b moves toward the second end 1b due to pulsed current application. As a result, the push part 15 moves the lock cam hole 83 of the lock cam part 8 toward the second end 1b due to the drive piston 6b. Then, the rotating cam part 9 of the push part 15 comes into contact with the driven projection 71 of the rotating part 7, so the push part 15 moves toward the second end 1b together with the rotating part 7 and the spool 5. State B is the state in which the driven projection 71 of the rotating part 7 has moved to a position outside the slide groove part 82 of the lock cam part 8. State C: Next, as shown in State C of Figures 34(C) and 36(b), the push portion 15 is in the state where it has moved furthest toward the second end 1b (full stroke). Then, as the first tracing surface 71a of the driven projection 71 is followed by the rotating cam surface 91a of the push portion 15, the rotating portion 7 is rotated by a certain angle.

[0089] (Second operation on the first attempt) In the following, state D in Figures 33(D) and 36(c) represents the second operation in this transition step. State D: As shown in State D of Figures 33(D) and 36(c), by de-energizing, the pilot air that was pressing the drive piston 6b is exhausted, and the return coil spring 11b of the biasing body 12 moves the spool 5 toward the first end 1a. Then, in conjunction with the spool 5, the rotating part 7 also moves toward the first end 1a. At this point, as a result of the above first operation, the driven projection 71 has moved from the position of the slide groove 82. Therefore, in State D, the driven projection 71 is driven by the first switching cam surface 81a of the switching cam part 81 of the lock cam part 8, and rotates further to be locked by the locking part 81c, resulting in a locked state. As described above, the switching valve 200 switches from the first position (unlocked state) to the second position (locked state) with a single pulse of energization and de-energization. The spool 5 is then held in the second position in the de-energized state.

[0090] Next, the transition operation from the locked state (D) to the unlocked state (A) in Figure 33 is shown in Figures 35 and 37. Figure 37 is a plan view of the lock cam mechanism 10, and is a schematic diagram showing the transition steps from the locked state (D) to the unlocked state (A). State D: State D in Figure 33 is a state where there is no power, and the driven projection 71 of the rotating part 7 is locked in place with the locking part 81c of the switching cam part 81.

[0091] (Second first operation) State E: With pulsed current flow, the drive piston 6b moves toward the second end 1b, as shown in State E of Figures 35(E) and 37(b). Then, the push part 15 moves the lock cam hole 83 of the lock cam part 8 toward the second end 1b due to the pressure of the drive piston 6b. The rotating part 7 then moves toward the second end 1b due to the pressure of the push part 15. State E shows the state in which the driven projection 71 of the rotating part 7 is disengaged from the locking part 81c of the switching cam part 81 of the lock cam part 8. State F: State F in Figures 35(F) and 37(b) is the state in which the rotating part 7 has moved furthest toward the second end 1b due to the application of power, i.e., the full stroke state. Then, the driven projection 71 is driven by the rotating cam surface 91a of the rotating cam part 9 of the push part 15, causing the rotating part 7 to rotate by a certain angle.

[0092] (Second operation of the second time) Figures 33(A) and 37(c) below illustrate the second operation in this transition step. State A: As shown in State A of Figures 33(A) and 37(c), by de-energizing, the air that was driving the drive piston 6b is exhausted, and the spool 5 moves toward the first end 1a due to the elastic force of the return coil spring 11b, which is the biasing part 11 of the biasing part body 12. The adjacent rotating part 7 also moves toward the first end 1a in conjunction with the spool 5. At this point, the driven projection 71 has moved from the position of the locking part 81c of the switching cam part 81 due to the rotation in the first operation described above. Therefore, as shown in Figure 37(c), in State F, the driven projection 71 is driven by the second switching cam surface 81b of the switching cam part 81 and returns to the slide groove part 82, resulting in the unlocked state. In this way, the spool 5 is held in the first position in the de-energized state.

[0093] Thus, the switching valve 200 of the present invention can alternately switch between two switching positions by a continuous operation of pulsed energization and de-energization. The spool is held in a de-energized state regardless of which switching position is selected.

[0094] This invention allows for the alternating switching between two switching positions through a series of switching operations involving pulsed energization and de-energization. The spool remains de-energized in both the first and second positions, effectively reducing power consumption. Furthermore, the switching position can be externally confirmed via an indicator.

[0095] Furthermore, the present invention is not limited to the disclosure described above, and can take various configurations without departing from the spirit of the invention. [Explanation of symbols]

[0096] 100 Two-position switching valve (first embodiment) 200 Two-position switching valve (second embodiment) 1a 1st end 1b 2nd end 2 valve holes 3. Multiple ports 4. Spool valve section 5 spools 51 Neck 52 Head 55 Connecting part 6 Drive Unit 7. Rotating part 71 Follower protrusion 71a First tracing surface 71b Second tracing surface 71c First slide surface 71d Second slide surface 72 Notch 73 Lid 74 Main body 75 Large diameter section 76 Small diameter section 8. Lock cam section 81 Switching cam section 81a First switching cam surface 81b Second switching cam surface 81c Locking part 81d Locking surface 81e First guide surface 81f Second guide surface 82 Slide groove 83 Lock cam hole 9. Rotating cam section 91 Rotating Cam 91a Rotating cam surface 10. Lock cam mechanism 11. Encouraging part 11a Return air spring 11b Return coil spring 12. Biasing body 13 Drive unit body 14 Valve casing 15 Push part 151 Sliding protrusion 16 Indicators 17 Pilot valve section 18 Lock Cam Body L axis P1 1st position P2 2nd position

Claims

1. A two-position switching valve having a spool valve section comprising a valve hole having a first end and a second end at both ends in the axial direction, a plurality of ports communicating with the valve hole, and a spool inserted into the valve hole so as to be movable in the axial direction, wherein the communication state between the plurality of ports can be switched by selectively holding the spool in a first position on the first end side and a second position on the second end side in the axial direction, The aforementioned two-position switching valve is A pilot valve section that supplies pilot air when power is applied, A drive unit that moves the spool toward the second end by supplying pilot air, and a biasing unit that elastically biases the spool toward the first end at all times, The device has a lock cam mechanism that can be selectively switched between a locked state, which locks the movement of the spool toward the first position at the second position, and an unlocked state, which releases the lock. The aforementioned lock cam mechanism is A rotating part connected to the spool on its axis, movable in the axial direction and rotatable around the axis, having a plurality of driven projections projecting radially from its outer surface, wherein the plurality of driven projections are arranged in a row in the circumferential direction at equal angular intervals around the axis, and the rotating part has a tracing surface at least one of its ends in the axial direction; A lock cam section having a plurality of switching cam sections, each having a switching cam surface that drives the tracing surface of the driven projection and a locking portion that prevents the rotating part from moving in the axial direction, and a plurality of sliding groove sections into which the driven projection is axially movable, arranged alternately in the circumferential direction on the inner circumferential surface of the lock cam hole into which the rotating part is inserted so as to be movable in the axial direction; A rotating cam section having a plurality of rotating cams arranged in an annular shape around an axis, each having a rotating cam surface that drives the tracing surface of the driven projection to rotate the rotating section around an axis; It consists of, A series of switching operations of the lock cam mechanism is performed by applying pulsed current to: a first operation in which the rotating part and the spool are moved toward the second end by energizing the pilot valve and causing the driven projection to follow the rotating cam, thereby rotating the rotating part by a certain angle around its axis; and a second operation in which the rotating part and the spool are moved toward the first end by the biasing part by de-energizing the pilot valve, The system can alternately switch between a locked state in which the driven projection of the rotating part engages with the locking portion of the lock cam portion to hold the spool in the second position, and an unlocked state in which the driven projection of the rotating part moves along the slide groove to hold the spool in the first position. A two-position switching valve characterized by the following features.

2. The aforementioned switching cam section is The device comprises a pair of guide surfaces extending in the axial direction and forming the side walls of the slide groove, and the end faces arranged at both ends in the axial direction, the end face at the second end having a first switching cam surface inclined with respect to the axis in a plan view, a second switching cam surface inclined in the same direction as the first switching cam surface, and a locking portion between the first switching cam surface and the second switching cam surface for engaging the driven projection. The first switching cam surface causes the driven projection to move to the locking portion, and the second switching cam surface causes the driven projection to move to the slide groove portion. The two-position switching valve according to feature 1.

3. The aforementioned rotating cam surface is an inclined surface that is tilted with respect to the axis in a plan view. The two-position switching valve according to claim 2, characterized by its features.

4. The driven projection has a pair of sliding surfaces that are parallel to each other in the axial direction and have different lengths, and a pair of end surfaces that connect the axial ends of the sliding surfaces to each other. The aforementioned tracing surface has an inclined surface parallel to the first switching cam surface and the rotating cam surface. The two-position switching valve according to feature 3.

5. The first switching cam surface and the rotating cam surface have an acute angle of inclination with respect to the axis in a plan view. The two-position switching valve according to feature 4.

6. The slide grooves are arranged around the axis at the same equal angular intervals as the driven projections of the rotating part. The rotating cam is arranged around the axis at equal angular intervals of half the distance between the driven projections of the rotating part. The two-position switching valve according to feature 4.

7. In the aforementioned two-position switching valve, The drive unit is positioned on the first end side of the spool valve unit, The lock cam portion is positioned on the second end side of the spool valve portion. The biasing portion is positioned on the second end side of the lock cam portion, The biasing portion has the rotating cam portion disposed at its first end, The plurality of driven projections of the rotating part have the following surfaces at both ends in the axial direction, the following surface at the first end follows the switching cam surface during the second operation, and the following surface at the second end follows the rotating cam surface during the first operation. The two-position switching valve according to feature 1.

8. The spool has a neck portion and a head portion that is larger in diameter than the neck portion, which extend coaxially from the end on the second end side. The rotating part is cylindrical with a lid on the first end, and has a notch formed from a part of the outer circumferential surface on the first end to the axial center portion of the lid. The spool and the rotating part are connected by locking them together in the axial direction, by inserting the head of the spool into the rotating part through the notch. The two-position switching valve according to claim 7, characterized by its features.

9. In the aforementioned two-position switching valve, The biasing portion is positioned on the second end side of the spool valve portion. The lock cam portion is positioned on the first end side of the spool valve portion. The drive unit is positioned on the first end side of the lock cam portion, The lock cam hole has a push portion that is not rotatable around the axis but movable in the axial direction, and the rotating cam portion is formed on the end face of the second end of the push portion. The plurality of driven projections each have a tracing surface at the first end of both ends in the axial direction, and the tracing surface follows the switching cam surface during the second operation and follows the rotating cam surface during the first operation. The two-position switching valve according to feature 1.

10. The push portion is formed in a cylindrical shape and has a sliding projection on its outer surface that slides against the sliding groove of the lock cam portion. The two-position switching valve according to claim 9, characterized in that it is as described in the previous version.

11. The spool has a cylindrical connecting portion extending coaxially from the end on the first end side, The rotating portion has a cylindrical large-diameter portion and a small-diameter portion on the first end side of the large-diameter portion, and the driven projection is formed spanning the large-diameter portion and the small-diameter portion. The connecting portion of the spool is rotatably inserted into the large-diameter portion of the rotating portion from the first end, and the small-diameter portion of the rotating portion is rotatably and reciprocally inserted into the push portion from the second end. The two-position switching valve according to claim 10, characterized by its features.

12. The biasing unit is a coil spring and / or an air spring. The two-position switching valve according to feature 1.

13. The two-position switching valve has an indicator that displays the switching position of the two-position switching valve. The two-position switching valve according to feature 1.

14. It has a valve casing having the spool valve portion inside, and a separate lock cam body having the lock cam portion inside, The valve casing and the lock cam body are connected to each other in the axial direction. The two-position switching valve according to feature 1.

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