JP2018179100A - Throttle-controlled electromagnetic valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a throttle-controlled electromagnetic valve which does not need a throttle valve.SOLUTION: A throttle-controlled electromagnetic valve includes a sleeve (12) and a spool (14), the spool includes spool blocks (21, 21) which adhere to s spool shaft (20) of the spool with a pair of intervals, the spool blocks have annular recesses (24) which are formed around the spool shaft, and also have a plurality of throttle holes 25a, 25b and 25c which are different in hole diameters passing to the annular recesses, electromagnets (34, 34) have movable iron cores (37) and fixed iron cores (36), and move the spool to the sleeve by pushing a push rod (41) when the movable iron cores are magnetically attracted to the fixed iron cores by the excitation of the electromagnets, one spool block (21) of the spool blocks the communication of a center chamber (15) and either of left and right chambers (16, 17), and the other spool block (21) makes the annular recesses (24) communicate with the other chamber via the throttle hole (25).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a solenoid valve, and more particularly to a throttle control type solenoid valve.

  For example, as a control method often used for a hydraulic circuit of a sub-acting hydraulic cylinder, as shown in FIG. 1, an electromagnetic valve 2 that switches the flow direction of pressure oil related to the operating direction of the hydraulic cylinder 1, and the operation of the hydraulic cylinder There is a combination with a throttling valve 3 which regulates the flow rate of hydraulic fluid which is related to speed. The solenoid valve 2, as schematically shown in FIG. 1, includes a sleeve constituting a partition valve seat and a spool with a land axially moved in contact with a cylindrical sliding surface, and is moved by the electromagnetic force of an electromagnet. The movable core is moved, and the spool is moved right or left through the push rod to switch the flow direction of the pressure oil. The hydraulic oil from the hydraulic pump P is made to flow into one end of the double acting hydraulic cylinder 1 from the port A, and the hydraulic oil is made to flow out from the other end of the cylinder to reach the tank T through the port B and the plunger of the hydraulic cylinder Or the other end of the cylinder to flow pressurized oil from port B and one end of the hydraulic cylinder to drain the pressurized oil through port A to tank T and the plunger of the hydraulic cylinder Pull back. The variable flow rate restricting valve 3 variably adjusts the flow rate of pressure oil flowing in and out of the cylinder in order to adjust the operation speed of the hydraulic cylinder. As described above, it is necessary to use two valves, a solenoid valve and a throttle valve, in the hydraulic circuit of the double acting hydraulic cylinder, and the juxtaposition of the two valves is a problem in achieving compactness of the mechanical equipment. It was

  An object of the present invention is to provide a solenoid valve with throttle control which does not require such a throttle valve separately.

  The object of the present invention is to move axially in a cylindrical sliding surface which constitutes a plurality of partition valve seats in a sleeve and to move therein, and in combination with the partition valve seats to open / close the valve. A central chamber adapted to communicate with the hydraulic pump and a left and right chambers respectively communicating with the port for the hydraulic cylinder, defined on the side of the central chamber in communication with the hydraulic pump, which is defined between the adjacent gate valve seats. An electromagnet, a fixed core fixedly provided to the magnetic attraction cartridge, a movable core disposed inside the cartridge so as to be axially movable and attracted toward the fixed core by the magnetic force of the electromagnet, and fixed A push rod, which penetrates the core and protrudes from the end face of the fixed core, is between the movable core and the spool shaft and comes into contact with each other, and the movable core is attracted to the fixed core When pressing the push rod protruding from the stationary core to move the spool from the neutral position to the left or right with respect to the sleeve, and when the magnetic force of the electromagnet demagnetizes, a return spring for returning the spool to the neutral position The movable core is pushed back from the fixed core via a push rod. In a solenoid valve, the spool includes a pair of spaced apart spool blocks fixed to its spool shaft, each spool block constituting a land Have an axially long land and a short land, and the longer land has an annular recess formed around the spool axis, and the longer land slips into the annular recess on its circumference A plurality of squeeze holes of different hole diameters arranged in a mutually offset manner, the movable core is attracted to the fixed core, and the push rod is pushed to squeeze the spool When moving it relative to one of the spools, one of the spool blocks is positioned so that its longer land cooperates with the gate valve seat to break the communication between the central chamber and one of the left and right chambers, and the other spool block This is achieved by providing a solenoid valve with throttling control that is positioned to communicate the annular recess with the other chamber through the throttling hole opened from the valve seat.

  In a preferred embodiment of the present invention, the plurality of throttle holes having different hole diameters comprises three types of throttle holes of large, medium and small, and in the minimum throttle position of the spool, all throttle holes are the central chamber and the other chamber In the middle throttle position medium and small throttle holes are open from the gate valve seat for communication between the central chamber and the other chamber in the middle throttle position, and in the maximum throttle position the small throttle hole And a throttle control solenoid valve arranged to be opened from the gate valve seat for communication between the central chamber and the other chamber.

  A further preferred embodiment of the present invention includes a screw mechanism for rotating the cartridge from the outside to move the cartridge in the backward direction, and the movement of the cartridge in the backward direction moves the fixed iron core from the minimum throttling position to the middle throttling position or the maximum throttling position. It is made to move, and this corresponds to the movement distance of the spool, that is, it is possible to adjust the projection length of the push rod from the fixed iron core when the push rod abuts on the spool, electromagnetic control with diaphragm control Provide a valve.

[Effect]
According to the present invention, assuming that the fixed iron core fixed to the cartridge is located at a position corresponding to the minimum throttling position, the movable iron core is moved toward the fixed iron core by the magnetic force generated by the biasing of the electromagnet on the right side. It moves and is attracted to the fixed core, and the movable core pushes the push rod to move the spool leftward from the neutral position to the minimum throttle position, thereby compressing the left return spring. One spool block of the spools disconnects the central chamber from the right chamber, and the other spool block connects the annular recess to the central chamber and the left chamber through the throttling hole opened from the valve seat, thus The pressure oil from the central chamber is throttled by the throttling hole and flows into the left chamber. It is obvious that the spool remains in that position while the electromagnet is energized. When the electromagnet is de-energized and the magnetic force of the electromagnet demagnetizes, the left compressed return spring expands to return the spool to the neutral position, and the movable iron core is pushed back to the original position by the push rod .

  As described above, the spool is moved to the middle throttle position or the maximum throttle position by moving the fixed core backward and adjusting the projection length of the push rod to move the push rod from the fixed core. It will be obvious that you can do it. The foregoing has described moving the spool to the left, but moving the spool to the right by the same operation as described above but the reverse operation to cut off the communication between the central chamber and the left chamber by one spool block, It is obvious that the other spool block allows the central chamber and the right chamber to be in communication through the throttling hole.

It is explanatory drawing which shows the combination of the conventional solenoid valve and a throttle valve. FIG. 1 is an overall partial cross-sectional view of a throttle control solenoid valve according to the present invention shown divided into two parts. FIG. 2 is a partial cross-sectional view of a portion of a throttle control solenoid valve according to the present invention, showing a minimum throttle position of a spool. It is a fragmentary sectional view which is a part of solenoid valve with a throttle control by this invention, and is shown by the maximum throttle position of a spool. FIG. 5 is a schematic longitudinal sectional view of a spool block showing a large, medium and small throttle hole arrangement;

  With reference to FIGS. 2 to 4, the solenoid valve 10 with a throttle control according to the present invention comprises a sleeve 12 having a cylindrical sliding surface that constitutes the partition valve seat 11, and an axial inside of the cylindrical sliding surface inscribed therein. And a spool 14 having a land 13 adapted to move and co-operating with the gate valve seat 11. A central chamber 15 and left and right chambers 16 and 17 on both sides thereof are defined between adjacent gate valve seats, and return chambers 18 and 19 are provided adjacent to the central chamber 15 and communicate respectively with tanks (not shown). The central chamber 15 is in communication with the hydraulic pump P, and the left and right chambers 16, 17 are in communication with port A and port B for the hydraulic cylinder, respectively.

  The spool 14 includes a pair of spaced apart spool blocks 21 and 21 fixed to the spool shaft 20. The spool blocks 21 and 21 are arranged to face each other in the axial direction in the figure, It may be arranged with the back facing. Each spool block 21 constitutes a land 13 which opens and closes in cooperation with the valve seat 11. The land 13 includes an axially long land 22 and a short land 23. Each spool block 21 has an annular recess 24 formed around the spool shaft 20 at the location of the longer lands 22 and the longer lands are arranged offset from one another on their circumference, A plurality of throttle holes 25 a, 25 b, 25 c having different hole diameters are formed in the annular recess 24. A plurality of throttling holes of different hole diameters consist of three types of large, medium and small throttling holes (Fig. 5), and at the minimum throttling position of the spool, all the throttling holes communicate with the central chamber and the other chamber Because the valve seat 11 is open, the middle and small throttle holes are opened from the gate valve seat 11 for communication between the central chamber and the other chamber in the middle throttle position, and the small throttle hole is opened in the maximum throttle position. It is arranged to be opened from the gate valve seat 11 for communication between the central chamber and the other chamber.

  The end plates 26, 26 are fixed to both ends of the sleeve 12 by connecting screws 26a, and the end plates 26, 26 are formed with deep counter bores 27 from the inside to the outside, and the stopper plate 28 is a return chamber 18 , 19 and fixed to the sleeve 12. A return spring 29 is disposed in the counterbore 27 and is received by a spring receiver 30 in contact with the stopper plate 28. The spool shaft 20 and its reduced diameter end 31 pass through the stopper plate 28 and the spring receiver 30, respectively, and the reduced diameter end 31 of the spool shaft is located in the countersunk hole 27. A shoulder 32 formed by the reduced diameter end 31 of the spool shaft 20 is adapted to abut against and push against the spring receiver 30 to compress the return spring 29 as the spool shaft 20 moves.

  Control plates 33, 33 are fixed to the end plates 26, 26 by bolts 34, and left and right electromagnets 34, 34 are provided adjacent to the control plates 33, 33. A cartridge 35 made of a magnetically permeable material is movably disposed through the electromagnets 34, 34 and has a fixed core 36 secured to its inner end, and also accommodates a moveable core 37 therein. The cartridge 35 is provided with a stopper / manual push button 38 at the end opposite to the stationary core. The push button is for manually moving the movable core when the power of the electromagnet is lost. As can be seen from FIG. 2, the stationary core 36 is in contact with the control plate 33, which corresponds to the minimum throttle position of the spool. The cartridge 35 is moved together with the stationary core 36 by the screw mechanism 35a by rotating the cartridge 35 from the outside. The screw mechanism 35a includes the male screw 35b of the fixed core 36 and the female screw 33a provided on the control plate 33, thus changing the moving amount of the fixed core 35 according to the rotation amount of the male screw 35 with respect to the female screw 35a. can do.

  A push rod 41 penetrates the fixed core 36 and is interposed between the movable core 37 and the end face of the spool shaft 20, and as described later, the push rod 41 protrudes from the fixed core 36 by the movement of the movable core. Is pushed thereby moving the spool 12 relative to the sleeve. The push rod 41 has a length that protrudes from the stationary core 36 by a length corresponding to the moving distance of the spool in a state in which the push rod 41 is in contact with the end surface of the spool shaft 20. The adjustment of the projection length of the push rod 41 from the fixed core 36 can be performed by moving the cartridge 35 and the fixed core 36 from the minimum throttle position (FIGS. 2 and 3) to the middle throttle position or the maximum throttle position (FIG. It is done by moving to 4). Reference numeral 39 denotes an adjustment nut for turning the cartridge, and reference numeral 40 denotes a lock nut for fixing the cartridge after adjustment.

  In operation, assuming that fixed iron core 36 is at a position corresponding to the minimum throttle position in contact with control plate 33 (FIG. 2), movable iron core 37 is fixed iron core by the magnetic force generated by the excitation of electromagnet 34 on the right. The push rod 41 is moved by the movable core 37 so as to move the spool 12 leftward from the neutral position to the minimum throttling position. The return spring 29 is compressed (FIG. 3). The right side spool block 21 of the spool 12 cooperates with the partition valve seat 11 to cut off the communication between the central chamber 15 and the right chamber 16 and brings the right chamber 16 and the return chamber 18 into communication, and the left spool block 21 The annular recess 24 communicates with the left chamber through all the throttle holes 25 opened from the gate valve seat. Therefore, the amount of pressure oil flowing from the central chamber 15 to the left chamber 17 is maximized. At this time, it is apparent that the communication between the left chamber 17 and the return chamber 19 is cut off.

  When the electromagnet is de-energized and the magnetic force demagnetizes, the left compressed return spring 29 extends and pushes the spool back to the neutral position, and the movable iron core 37 is pushed back to the original position by the push rod 41. Be

  When the spool 12 is to be moved from the minimum throttle position to the middle throttle position or the maximum throttle position (FIG. 4 is a view at the maximum throttle position), the cartridge 35 is turned to fix the stationary core 36 by the method described above. The push rod 41 retracts and shortens the protruding length of the push rod 41 from the fixed iron core 36 when the push rod 41 abuts on the end face of the spool shaft 20. In order to move the spool 12 from the maximum throttling position to the middle throttling position or the minimum throttling position, the cartridge 35 may be rotated in the opposite direction to move the fixed iron core 36 forward.

  Further, the spool 12 is moved to the right by performing the same operation as the above but the reverse operation. By doing so, the left spool block 21 breaks the communication between the central chamber 15 and the left chamber 17 and brings the left chamber 17 and the return chamber 19 into communication, and the right spool block 21 makes the central chamber 15 and the right chamber 16 It will be apparent that the communication is to be made and the right chamber 16 and the return chamber 18 be disconnected.

  As described above, according to the present invention, since the annular recess is formed in the spool block of the spool and a plurality of throttle holes having different hole diameters to be escaped are provided in the annular recess, flow path switching and pressure oil flow restriction are simultaneously performed. It is very convenient. Moreover, since it is not necessary to attach a throttle valve separately, a small-sized solenoid valve with throttle control can be provided.

Reference Signs List 10 solenoid valve 11 partition valve seat 12 sleeve 13 land 14 spool 15 central chamber 16 chamber 17 chamber 18 return chamber 19 return chamber P hydraulic pump A port B port 20 spool shaft 21 spool block 22 long land 23 short land 24 annular recess 25a throttle Hole 25b Throttle hole 25c Throttle 26 End plate 27 Counterbore 28 Stopper plate 28 Return spring 30 Spring retainer 31 Reduced diameter end 32 Shoulder 33 Control plate 34 Electromagnet 35 Cartridge 36 Fixed iron core 37 Movable iron core 38 Stopper and manual push button 35a screw mechanism 35b male screw 33a female screw 41 push rod

Claims (3)

  And a spool having a land which opens and closes in cooperation with the partition valve seat so as to move in the axial direction in contact with a cylindrical sliding surface which constitutes a plurality of partition valve seats on the sleeve A central chamber in communication with the hydraulic pump, which is defined between the adjacent partition valve seats, and left and right chambers respectively communicating with ports for the hydraulic cylinder on both sides thereof, electromagnets on the left and right, inside the magnetic attraction cartridge A fixed iron core provided in the cartridge, a movable iron core disposed in the cartridge so as to be axially movable and attracted toward the fixed iron core by the magnetic force of the electromagnet, and an end face of the fixed iron core penetrating the fixed iron core Protruding from the stationary core when the movable iron core is adsorbed to the fixed iron core, and the push rod that is between the movable iron core and the spool shaft and comes into contact with each other. And a return spring for returning the spool to the neutral position when the push rod is pushed to move the spool from the neutral position to the right or left with respect to the sleeve and the magnetic force of the electromagnet demagnetizes; In a solenoid valve that is pushed back from a stationary core via a push rod, the spool includes a pair of spaced apart spool blocks secured to its spool shaft, each spool block being an axially long land that constitutes a land And shorter lands, and the longer lands have an annular recess formed around the spool axis, the longer lands being arranged offset relative to one another on the circumference into the annular recess The movable iron core is attracted to the fixed iron core, and the push rod is pushed to move the spool relative to the sleeve. The one spool block of the spool is positioned so that the longer land cooperates with the gate valve seat to disconnect the central chamber and one of the left and right chambers, and the other spool block has its annular recess. A solenoid valve with a throttle control positioned to communicate with the other chamber through a throttle hole opened from the valve seat.   A plurality of throttling holes of different hole diameters consist of three types of large, medium and small throttling holes, and at the minimum throttling position of the spool, all the throttling holes are gate valves for communication between the central chamber and the other chamber Open from the seat, in the middle throttle position, the middle and small throttle holes are open from the gate for communication between the central chamber and the other chamber, and in the maximum throttle position, the small throttle holes are the central chamber and the other chamber The solenoid valve with throttling control according to claim 1, wherein the solenoid valve is arranged to be opened from the gate valve seat for communication with the.   The screw mechanism includes a screw mechanism for rotating the cartridge from the outside to move the cartridge in the backward direction, and moving the fixed iron core from the minimum squeezing position to the middle squeezing position or the maximum squeezing position by moving the cartridge in the backward direction. A solenoid valve with aperture control, which can adjust the projection length of the push rod from the fixed core when the push rod abuts on the end face of the spool shaft, which corresponds to the distance.

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