JP2012225496A - Directional control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a directional control valve capable of selectively opening/closing two flow outlets, fully opening the two flow outlets, and achieving a higher speed and energy saving of flow path switching.SOLUTION: Two control valves 21 and 22 having a pilot type valve form are arranged between a flow inlet 10 and two flow outlets 11 and 12. Between the two control valves 21 and 22 and a stepping motor 15, a reverse operation device having two screw feeding mechanisms 55 and 56 opposite to each other in feeding directions is disposed to perform opening/closing drive of the two control valves 21 and 22 in opposite directions.

Description

  The present invention relates to a directional switching valve suitable for use in a heat pump type air conditioning system and the like, and in particular, has one inflow port and two outflow ports, and the two outflow ports can be selectively opened and closed. The present invention relates to a direction switching valve.

  In a heat pump type air conditioning system such as a car air conditioner, it may be required to distribute refrigerant from a compressor to two heat exchangers at the same time. Conventionally, for example, Patent Document 1 (in particular, the electromagnetic valve 4 and FIG. 13), two electromagnetic valves (ON / OFF valves) are used to meet the above needs.

  Moreover, as a direction switching valve, it has one inflow port and two outflow ports, and opens and closes two outflow ports selectively by rotating a valve body with rotation drive sources, such as a stepping motor. Thus, a three-way switching valve adapted to switch the direction (flow path) is well known.

Japanese Patent Laid-Open No. 9-295506

  However, in the method using two solenoid valves, when the refrigerant from the compressor is distributed to two heat exchangers at the same time, it is necessary to keep the two solenoid valves fully open. There is a problem that the solenoid valve must be energized for a long time, resulting in increased power consumption.

  In addition, conventional three-way switching is performed by selectively opening and closing the two outlets by rotating the valve body with a rotational drive source such as a stepping motor. In addition to the problem that the switching valve requires a relatively long time for the switching valve, the two outlets cannot normally be fully opened, so the above needs (the refrigerant from the compressor is distributed to the two heat exchangers at the same time) However, even if it can be made, there is a problem that a rotational drive source such as a stepping motor must be rotated for a considerably long time before both outlets are fully opened.

  Further, there is a similar problem when the refrigerant from the compressor is distributed simultaneously or selectively to three or more heat exchangers.

  The present invention has been made in view of the above circumstances, and its object is to selectively open and close two or a plurality of outlets, and to fully open both two or a plurality of outlets. Another object of the present invention is to provide a directional switching valve that can be used to speed up the flow path and save energy.

  In order to achieve the above object, a directional switching valve according to the present invention basically includes a valve body provided with an inlet and two outlets, and a gap between the inlet and the two outlets. Two control valves arranged, and a single rotational drive source for opening and closing the two control valves, the two controls between the rotational drive source and the two control valves A reverse motion device having two screw feed mechanisms with opposite feed directions for opening and closing the valves in opposite directions is provided.

  In a preferred embodiment, both the two control valves can be fully opened by stopping the reverse movement device in a specific state.

  The reverse movement device preferably includes a first screw feed mechanism having a first male screw member and a first female screw member made of a left-hand screw, and a second male screw member and a second female screw member made of a right-hand screw. A second screw feed mechanism, a drive gear composed of a straight tooth spur gear that is rotationally driven by the rotational drive source, a first driven gear that is provided on the first male screw member and meshes with the drive gear, And a second driven gear that is provided on the male screw member and meshes with the drive gear, and the first and second driven gears mesh with the drive gear by the thrust of the first and second screw feed mechanisms, respectively. While sliding in the axial direction.

  In another preferred embodiment, at least one of the two control valves takes the form of a direct acting needle valve.

  In yet another preferred embodiment, at least one of the two control valves is in the form of a pilot valve.

  The control valve in the form of a pilot-type valve is preferably a piston-type main valve body, the main valve body is slidably inserted, and the main valve body has a back pressure chamber and a main valve chamber. A pilot passage for releasing the pressure of the back pressure chamber to the outlet, and a pilot valve body for opening and closing the pilot passage, wherein the pilot valve body is the screw. A male screw member of the feed mechanism is configured.

In another preferred embodiment, a speed reduction mechanism is provided between the rotation drive source and the reverse movement device.
In another preferred embodiment, the speed reduction mechanism is a mysterious planetary gear type speed reduction mechanism.

In another preferred embodiment, a stepping motor is used as the rotational drive source.
In another preferred aspect, a stepping motor is used as the rotational drive source, and the mysterious planetary gear type reduction mechanism is attached to the stepping motor.

  Further, the direction switching valve according to the present invention includes a plurality of control valves and a single rotation drive source for driving the plurality of control valves, and is provided between the rotation drive source and the plurality of control valves. In addition, there is provided a reverse motion device having two types of screw feed mechanisms having reverse feed directions for driving a plurality of control valves previously divided into two groups in opposite directions for each group. It is characterized by that.

  In a preferred embodiment of the direction switching valve according to the present invention, two feed valves having opposite feed directions are driven between a rotary drive source such as a stepping motor and the two control valves so as to open and close the two control valves in opposite directions. Since a reverse drive device having a single screw feed mechanism is provided, the rotation of the rotary drive source is transmitted to, for example, the drive gear → the driven gear → the screw feed mechanism → the valve body of the control valve. The valve bodies move in opposite directions. As a result, the two outlets can be selectively opened and closed, and the reverse movement device is stopped in a specific state, for example, in a state where the valve bodies of the two control valves are fed by a predetermined pitch from the origin position by the screw feed mechanism. Thus, the two control valves (two outlets) can be fully opened together.

  Therefore, the directional control valve of the present invention can be used in place of the two solenoid valves in a heat pump type air conditioning system that requires the refrigerant from the compressor to be simultaneously distributed to the two heat exchangers as described above. . In this case, in the direction switching valve of the present invention, after the two outlets are fully opened, the fully opened state is maintained without energization. Is planned.

  In addition, by adopting a pilot type valve as the control valve, it is possible to open and close the large-diameter outlet with a small driving force, and to open the two control valves (outlet), the pilot Even if a relatively small (small output) stepping motor (+ planetary gear type reduction mechanism) is used as the rotational drive source, the valve body only needs to be lifted slightly. Compared to conventional three-way switching valves, etc. The flow path can be switched quickly, and the flow path responsiveness is improved.

  Furthermore, in the directional control valve according to the present invention, the valve bodies of the plurality of control valves divided into two groups move in opposite directions for each group, so that the plurality of control valves can be selectively opened and closed. Each control valve can be fully opened.

The longitudinal cross-sectional view which shows the operation state (1st outflow port full open, 2nd outflow port full close) of one Embodiment (1st Example) of the direction switching valve which concerns on this invention. Sectional drawing which shows the operation state (1st outflow port fully closed, 2nd outflow port full open) of 1st Example. Sectional drawing which shows the operation state (A 1st outflow port and a 2nd outflow port are both fully open) of 1st Example. Sectional drawing which shows 2nd Example of the direction switching valve which concerns on this invention.

Embodiments of the present invention will be described below with reference to the drawings.
1, 2 and 3 are longitudinal sectional views showing different operating states of an embodiment (first example) of the direction switching valve according to the present invention.

  The direction switching valve 1 of the first embodiment shown in the drawing is, for example, the two solenoid valves described above in a heat pump type air conditioning system such as a car air conditioner that is required to simultaneously distribute refrigerant from a compressor to two heat exchangers. The valve body 2 having an inlet 10 and two outlets (first outlet 11 and second outlet 12) and a stepping motor 15 as a rotational drive source are used instead.

  The valve body 2 includes a bottomed cylindrical motor mounting portion 2A and a cylindrical base portion 2B with a hole, and a stepping motor 15 is mounted on the motor mounting portion 2A. The stepping motor 15 includes a base portion 41 having a convex cross-sectional outer shape that is screwed and fixed to the motor mounting portion 2A, a cylindrical holding guide member 42 that is press-fitted and fixed to the base portion 41, and the base portion. A refrigerant sealing can 18 whose lower end is welded to the base portion 41, a rotor 16 disposed on the inner peripheral side of the can 18, and a stator coil 17 fitted on the outer periphery of the can 18. An air gap α is formed between the stator coil 17 and the rotor 16. The motor 15 is provided with a mysterious planetary gear type reduction mechanism 40, and the rotation of the output shaft 43 of the motor 15 (the output shaft of the mysterious planetary gear type reduction mechanism 40) is connected in the central insertion hole 41a. It is transmitted to the shaft 45. In this example, the planetary gear speed reduction mechanism 40 reduces the rotation of the rotor 16 to about 1/45 and outputs it.

  The articulated rotating shaft 45 passes through the lower cylindrical portion 41b of the motor mounting portion 2A, and the lower end portion thereof is supported by a pivot hole 53 provided at the center of the bottom portion 2b of the motor mounting portion 2A. A drive gear 50 made of a spur gear is fixed integrally (the articulation rotating shaft 45 is a shaft portion of the drive gear 50). The drive gear 50 is slidably rotated on the bottom 2b of the motor mounting portion 2A.

  In the base body portion 2B of the valve body 2, stepped vertical holes 4 penetrating vertically are arranged side by side. In FIG. 3, a first control valve 21 is disposed in the left vertical hole 4, and a valve seat member 5 provided with a first outlet 11 with a valve seat 11 a at a lower portion thereof is screwed and fixed. A second control valve 22 is disposed in the vertical hole 4, and a valve seat member 5 having a second outlet 12 with a valve seat 12 a provided at a lower portion thereof is screwed and fixed. Further, on the front side (front side in the figure) of the base body 2B, a horizontal hole-shaped inlet 10 is provided so as to be connected to the left and right vertical holes 4 together.

  The first control valve 21 and the second control valve 22 have the same basic configuration and each take a pilot type valve configuration. Hereinafter, the first control valve 21 will be described mainly (representatively). The first control valve 21 (22) includes a piston-type main valve body 23, and the main valve body 23 is slidably inserted. The main valve body 23 allows the back pressure chamber 26 and the main valve chamber 25 to A pilot passage 27 for releasing the pressure of the back pressure chamber 26 to the outlet 11 (12), and a pilot valve body 31 (32) for opening and closing the pilot passage 27 And.

  More specifically, a sleeve 24s into which the main valve element 23 (the upper large diameter portion 23a) is slidably inserted is fitted and fixed to the upper portion of the insertion chamber 24, and the main valve in the insertion chamber 24 is fixed. A back pressure chamber 26 is formed above the body 23, and a main valve chamber 25 is formed below the main valve body 23. The main valve body 23 includes an upper large-diameter portion 23a, an intermediate small-diameter portion 23b, and a valve body portion 23c. The lower surface of the valve body portion 23c is separated from and in contact with the valve seat 11a (12a). An annular sealing material 23d made of rubber, Teflon (registered trademark) or the like that opens and closes 11 (12) is fixed by caulking, for example. In addition, an annular convex portion 23s that protrudes from the upper end outer peripheral portion of the large-diameter portion 23a of the main valve body 23 to contact the ceiling surface of the insertion chamber 24 and determines the maximum lift position of the main valve body 23 is provided. Further, a sealing material (piston ring) 23f is mounted on the outer periphery of the large diameter portion 23a. In order to urge the main valve body 23 upward (in the valve opening direction), a valve opening spring 28 formed of a compression coil spring is compressed between the upper large diameter portion 23a and the outer periphery of the valve seat 11a (12a). It is disguised.

  On the other hand, a pilot passage 27 with a valve seat 27a for allowing the pressure in the back pressure chamber 26 to escape to the outflow port 11 (12) is provided in the center of the main valve body 23. The pilot passage 27 is opened and closed. Therefore, the pilot valve body 31 (32) is arranged so as to be in contact with and away from the valve seat 27a.

  The pilot valve body 31 (32) is a valve body portion in which a circular sealing material 30d made of rubber or Teflon (registered trademark) or the like that opens and closes the pilot passage 27 by being connected to the valve seat 27a is caulked and fixed to the lower surface thereof. 30a, a valve stem portion 30b, and an upper end small diameter shaft portion 30c.

  The valve rod portion 30b of the pilot valve body 31 of the first control valve 21 is provided with a male screw portion (hereinafter, referred to as a left male screw portion 31e) formed of a left screw, and this left male screw portion 31e. Is screwed into a female screw portion (hereinafter referred to as a left female screw portion 33i) consisting of a left screw of a fixing nut member 33 fixed to the left vertical hole 4 by a press fit or the like in the small vertical stepped upper vertical hole portion 4a. Yes. In this embodiment, the pilot valve body 31 provided with the left male thread portion 31e and the fixing nut member 33 provided with the left female thread portion 33i move downward when rotated counterclockwise (counterclockwise). A left screw feed mechanism 55 is configured to move upward when rotated clockwise (clockwise).

  A first driven gear 51 made of a straight tooth spur gear meshing with the drive gear 50 is integrally fixed to the upper end small diameter shaft portion 30 c of the pilot valve body 31 of the first control valve 21.

  On the other hand, the valve rod portion 30b of the pilot valve body 32 of the second control valve 22 is provided with a male screw portion (hereinafter, referred to as a right male screw portion 32e), and this right male screw portion 32e. Are screwed into a female thread portion (hereinafter referred to as a left female thread portion 34i) consisting of a left-hand thread of a fixing nut member 34 fixed to the upper vertical hole portion 4a with a small diameter step of the right vertical hole 4 by press fitting or the like. Yes. In this embodiment, when the pilot valve body 32 provided with the left male screw portion 32e and the fixing nut member 34 provided with the left female screw portion 34i are rotated clockwise (clockwise), they move downward. Rotating counterclockwise (counterclockwise) constitutes a right screw feed mechanism 56 that moves upward when the feed direction is opposite to the left screw feed mechanism 55.

  A second driven gear 52 formed of a straight tooth spur gear meshing with the drive gear 50 is integrally fixed to the upper end small diameter shaft portion 30 c of the pilot valve body 32 of the second control valve 22.

  Therefore, in this embodiment, the left screw feed mechanism 55, the right screw feed mechanism 56, the drive gear 50, the first driven gear 51, and the second driven gear 52 constitute a reverse device, and the first The second driven gears 51 and 52 slide in the axial direction while meshing with the drive gear 50 by the screw feed thrusts of the first and second screw feed mechanisms 55 and 56, respectively.

  Further, in the direction switching valve 1 of the present embodiment, the inlet 10 is formed between the main valve chambers 25-25 of the first control valve 21 and the first control valve 22, and the inlet 10 is the first control valve 21. And the first control valve 22 communicate with the main valve chambers 25, 25, respectively, and the pilot passages 27, 27 (one of the two must be open) and the screw feed mechanisms 55, 56 have a female screw-female screw gap. The upper vertical hole 4a and the lower cylindrical portion 41b of the motor mounting portion 2A are also communicated with each other through the like, so that the inlet 10, the left and right main valve chambers 25, 25, the upper vertical hole 4a, 4a and the lower The inside of the cylindrical portion 41b and the like is filled with a high-pressure (isobaric) refrigerant.

Further, in the first control valve 21 and the first control valve 22 each taking a pilot type valve configuration, the pressure of the main valve chamber 25 is P1, the pressure of the back pressure chamber 26 is P2, and the pressure of the outlets 11 and 12 is P3. The horizontal cross-sectional area of the back pressure chamber 26 (pressure receiving area of the main valve body 23) is Ap, the horizontal cross-sectional area of the outlets 11 and 12 is Av, the urging force of the valve opening spring 28 is Pf, and the main valve body 23 is pushed up. If the force is the valve opening force and the force that pushes down the main valve body 23 is the valve closing force, the valve opening conditions of the first control valve 21 and the first control valve 22 are:
Valve closing force = P2 x Ap <valve opening force = P1 x (Ap-Av) + P3 x Av + Pf
It becomes.

  In the direction switching valve 1 configured as described above, when the motor 15 is energized in a predetermined manner to rotate the drive gear 50, for example, counterclockwise, the driven gears 51 and 52 rotate in the axial direction while rotating clockwise. The pilot valve body 31 of the first control valve 21 moves upward by the screw feed of the left screw feed mechanism 55, and the pilot valve body 32 of the second control valve 22 moves to the right screw. The feed mechanism 56 moves downward.

  As shown in FIG. 1, the pilot valve body 31 of the first control valve 21 is pulled up to the highest position to open the pilot passage 27, and the pilot valve body 32 of the second control valve 22 closes the pilot passage 27. When the first control valve 21 (first outlet 11) is fully opened (in this state, the refrigerant from the inlet 10 flows only to the second outlet 12), the motor 50 is predetermined from this state. When the drive gear 50 is rotated clockwise by a predetermined angle by energizing in this manner, the pilot valve body 31 of the first control valve 21 is brought to the lowest position by the screw feed of the left screw feed mechanism 55 as shown in FIG. The pilot passage 27 is closed by moving, and the pilot valve body 32 of the second control valve 22 is moved to the highest position by the right screw feed mechanism 56 to open the pilot passage 27. As a result, the second control valve 22 becomes [valve closing force <valve opening force], and the main valve body 23 rises to the maximum lift position where the annular convex portion 23s comes into contact with the ceiling stopper portion 35s. The two outlets 12 are fully opened. On the other hand, in the first control valve 21, [valve closing force> valve opening force], and the main valve body 23 closes the first outlet 11. Therefore, in this state, the refrigerant from the inlet 10 flows only to the second outlet 12. The main valve body 23 can also be seated on the valve seat 11a by pressing of the pilot valve body 31 before [valve closing force> valve opening force].

  Next, from the state where the pilot valve body 32 is at the highest position (the state where only the second outlet 12 is open), the motor 50 is energized in a predetermined manner, and the drive gear 50 is made approximately half the predetermined angle. When rotated clockwise, the pilot valve body 31 of the first control valve 21 is moved upward by about half of the above-described opening / closing operation by the screw feed of the left screw feed mechanism 55, and the pilot valve body 32 of the second control valve 22. Is moved downward by about half of that during the opening / closing operation described above by the right screw feed mechanism 56, the height positions of both pilot valve bodies 31, 32 become substantially the same, and both pilot passages 27 are opened. Therefore, at this time, both the first control valve 21 and the second control valve 22 are fully opened, and the refrigerant from the inlet 10 flows to both the first inlet 11 and the second outlet 12.

  In addition, although energization to the motor 15 is stopped after the above opening / closing operation is completed, the two control valves 21 and 22 maintain the above-described state.

  As described above, in the direction switching valve 1 of the present embodiment, between the stepping motor 15 and the two control valves 21 and 22, the two control valves 21 and 22 are driven to open and close in opposite directions. Since the reverse movement device having the two screw feed mechanisms 55 and 56 having the opposite feed directions is provided, the pilot valve bodies 31 and 32 of the two control valves 21 and 22 can be moved in the opposite directions. Thus, the two outlets 11 and 12 can be selectively opened and closed, and the two screw feed mechanisms 55 and 56 are stopped in a specific state, whereby the two control valves 21 and 22 (the two outlets 11 and 12 12) can be fully opened together.

  Therefore, as described above, the direction switching valve 1 of this embodiment is used in place of the two solenoid valves in the heat pump type air conditioning system that requires the refrigerant from the compressor to be simultaneously distributed to the two heat exchangers. Can do. In this case, in the direction switching valve 1 of the present embodiment, after the two outlets 11 and 12 are both fully opened, the fully opened state is maintained without energization. Therefore, compared to the case where two solenoid valves are used. Energy saving and so on.

  In addition, by adopting a pilot valve as the control valve, the large outlet can be opened and closed with a small driving force, and the two control valves 21 and 22 (outlets 11 and 12). Since the pilot valve bodies 31 and 32 need only be lifted slightly to open the valve, even if a relatively small (small output) stepping motor (15+ planetary gear speed reduction mechanism 40) is used as a rotational drive source, Compared with a three-way switching valve or the like, the flow path can be switched quickly, and the flow path switching response is improved.

  The direction switching valve according to the present invention is not limited to the configuration of the direction switching valve 1 of the first embodiment described above, and various changes can be made.

  For example, in the first embodiment, the two control valves 21 and 22 are both pilot-type valves, but like the direction switching valve 1 ′ of the second embodiment shown in FIG. As the two control valves 21 ′ and 22 ′, a direct acting type having needle valve bodies 31 ′ and 32 ′ may be adopted, and the small-diameter outlets 11 ′ and 12 ′ may be opened and closed. The two control valves 21 ′ and 22 ′ (two outlets 11 ′ and 12 ′) can be fully opened, and the same effect as in the first embodiment can be obtained.

  Further, a pilot-type control valve (first embodiment) and a direct acting needle valve (second embodiment) may be provided in a single motor-operated valve.

  Furthermore, as long as it is driven by raising or lowering or rotating the left screw feed mechanism and the right screw feed mechanism, the form of the valve driven by each screw feed mechanism is any form other than the first and second embodiments described above. It may be a valve. That is, for example, a rotary valve such as a ball valve that switches the flow path by rotating may be connected to the left screw feed mechanism and / or the right screw feed mechanism without the rotary valve moving up and down. For example, one of the left screw feed mechanism and / or the right screw feed mechanism tip (the tip of the male screw portion) and the rotary valve is provided with a convex portion having a rectangular cross section that protrudes in the direction of the rotation center axis of the rotary valve. On the other hand, if a concave portion that engages with the convex portion is provided, when the rotation of the screw feed mechanism is transmitted to the rotary valve, the convex portion or the concave portion slides in the central axis direction of the rotary valve, and the screw Only the rotation of the feed mechanism is transmitted to the rotary valve, and the rotary valve is prevented from moving up and down.

  Furthermore, in the above description, the driven gear 50 has two driven gears (first driven gear 51 and second driven gear 52) meshed with each other, and two screw feed mechanisms (left and right feed screw mechanisms 55). , 56), the two control valves are driven. However, the present invention is not limited to this, and three or more control valves are connected to a plurality of left and right screw feed mechanisms. It is also possible to use and control the drive. That is, a plurality of control valves are divided into two groups in advance, and a left-handed screw feed mechanism is used individually for driving each control valve in one group, and individually for driving each control valve in the other group. A right screw feed mechanism may be used, and the driven gear of each screw feed mechanism may be engaged with the drive gear 50. In this case, each screw feed mechanism is arranged on the circumference of a circle centered on the rotation axis of the drive gear 50.

1 direction switching valve 2 valve body 10 inlet 11 first outlet 12 second outlet 15 stepping motor 21 first control valve 22 second control valve 23 main valve body 24 insertion chamber 25 main valve chamber 26 back pressure chamber 27 Pilot passage 28 Valve opening spring 31 Pilot valve body 31e Left male thread part 32 Pilot valve body 32e Right male thread part 33 Fixed nut member 33i Left female thread part 34 Fixed nut member 34i Right female thread part 40 Planetary gear speed reduction mechanism 43 Output Shaft 45 Connection rotating shaft 50 Drive gear 51 First driven gear 52 Second driven gear 55 Left screw feed mechanism 56 Right screw feed mechanism

Claims (11)

A valve body provided with an inlet and two outlets, two control valves respectively disposed between the inlet and the two outlets, and a single unit for opening and closing the two control valves. A direction switching valve that can selectively open and close the two outlets by the two control valves,
Between the rotational drive source and the two control valves, a reverse device having two screw feed mechanisms with opposite feed directions is provided to open and close the two control valves in opposite directions. A directional control valve characterized by comprising:   The direction switching valve according to claim 1, wherein the two control valves can be fully opened by stopping the reverse movement device in a specific state.   The reverse movement device includes a first screw feed mechanism having a first male screw member and a first female screw member made of a left screw, and a second screw member having a second male screw member and a second female screw member made of a right screw. A screw feed mechanism; a drive gear composed of a straight tooth spur gear driven to rotate by the rotational drive source; a first driven gear provided on the first male screw member and meshing with the drive gear; and the second male screw A second driven gear that is provided on the member and meshes with the drive gear, and the first and second driven gears are engaged with the drive gear by the thrust of the first and second screw feed mechanisms, respectively. The direction switching valve according to claim 1, wherein the direction switching valve is configured to slide in a direction.   The direction switching valve according to any one of claims 1 to 3, wherein at least one of the two control valves is a direct acting needle valve.   The directional control valve according to any one of claims 1 to 3, wherein at least one of the two control valves has a pilot-type valve configuration.   The control valve in the form of a pilot type valve has a piston-type main valve body, the main valve body is slidably inserted, and is divided into a back pressure chamber and a main valve chamber by the main valve body. A pilot passage for releasing the pressure of the back pressure chamber to the outlet, and a pilot valve body for opening and closing the pilot passage, the pilot valve body of the screw feed mechanism 6. The directional control valve according to claim 5, wherein the directional switching valve constitutes a male screw member.   The direction switching valve according to claim 1, wherein a speed reduction mechanism is provided between the rotation drive source and the reverse movement device.   The direction switching valve according to claim 7, wherein the speed reduction mechanism is a mysterious planetary gear type speed reduction mechanism.   The direction switching valve according to claim 1, wherein a stepping motor is used as the rotation drive source.   9. The direction switching valve according to claim 8, wherein a stepping motor is used as the rotation drive source, and the mysterious planetary gear type reduction mechanism is attached to the stepping motor. A direction switching valve comprising a plurality of control valves and a single rotational drive source for driving the plurality of control valves,
Between the rotary drive source and the plurality of control valves, two types of control valves that are divided into two groups in advance are driven in opposite directions for each group. A direction switching valve characterized in that a reverse movement device having a screw feed mechanism is provided.

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