JP2008144839A - Spool valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spool valve capable of solving inconvenience by deformation or the like. <P>SOLUTION: A straight part 42 is formed on a base end side of a spool 12 and a peripheral surface 24 constituting the straight part 42 is slide-contacted with a slide-contact surface 25 to open/close an input groove 23 of an input port 21. A control area 51 having an outer shape dimension varied as it advances toward a distal end side is set on a distal end side more than the straight part 42, and is constituted by a first taper part 61 provided on a distal end side than the straight part 42, a second taper part 62 provided at a distal end side than the first taper part 61, and a third taper part 63 provided on a portion from the second taper part 62 to the distal end. A first taper angle θ1 of the first taper part 61, a second taper angle θ2 of the second taper part 62 and a third taper angle θ3 of the third taper part 63 are set different from one another. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a spool valve that controls a flow rate, for example.

  Conventionally, when the flow rate is controlled, a spool valve is used, and the spool valve is configured to control the flow rate by adjusting the opening of the port.

  In such a spool valve, the control flow rate is determined by the shape of the port opening and the position of the spool. Therefore, a desired flow rate characteristic can be obtained by appropriately selecting the shape of the port opening and the spool control position. it can.

  Here, in order to arbitrarily control the spool control position, the product shape is increased, which is not desirable. For this reason, desired flow characteristics are achieved by appropriately selecting the opening shape.

  FIG. 3A is a view showing such a spool valve 801, and the spool 802 of the spool valve 801 is formed of a cylindrical member as shown in FIG. 3B. At the tip of the spool 802, triangular cutouts 803 and 803 are provided opposite to each other, and slits 804 and 804 are formed on the back side of the cutouts 803 and 803, respectively.

  As a result, as shown in FIG. 3A, the position of the notches 803 and 803 with respect to the input port 811 is controlled by controlling the position of the spool 802 in the length direction. The flow rate of oil input from the port 811 via the notches 803 and 803 can be controlled.

  However, in such a spray valve 801, the notches 803 and 803 are formed at the end of the cylindrical spool 802, so that the end of the spool 802 is intermittent, and the rigidity of the outer periphery of the spool 802 is increased. Will fall.

  For this reason, in the heat treatment or finishing process after forming the notches 803 and 803 in the spool 802, the outer peripheral portion may be deformed or distorted, and the roundness may be reduced.

  In this case, if the sliding clearance of the spool 802 is small, a sliding failure may occur due to this deformation, which may cause abnormal operation.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a spool valve that can eliminate problems caused by deformation and the like.

  In order to solve the above-mentioned problems, in the spool valve according to claim 1 of the present invention, the cylindrical spool is operated in the axial direction to open and close the port provided on the sliding contact surface where the peripheral surface of the spool is in sliding contact. In the spool valve for controlling the flow rate from the port, a control region having a smaller diameter than the proximal end portion and changing in outer dimension as it goes toward the distal end portion is set at the distal end portion of the spool.

  That is, a control region in which the outer dimensions change toward the tip side is set at the tip of the spool, and in this control region, the peripheral surface of the spool and the slidable contact surface on which the peripheral surface is in sliding contact The gap formed between them changes according to the external dimensions.

  For this reason, by operating the spool in the axial direction with respect to the port formed on the sliding contact surface, the gap between the peripheral surface of the spool and the sliding contact surface can be varied. Thus, the flow rate through the port is varied.

  Further, in the spool valve according to claim 2, a plurality of taper portions having a diameter reduced from the base end side toward the tip end side are provided in the axial direction to constitute the control region, and the peripheral surface of each taper portion and the spool The angle of inclination formed by the central axis of was set to a different angle.

  That is, the control region is composed of a plurality of tapered portions provided in the axial direction, and the inclination angles formed by the peripheral surface of each tapered portion and the central axis of the spool are set to different angles. .

  For this reason, the target flow characteristic is acquired by setting the length of the direction of an axis of each taper part, and the angle in each taper part according to a use.

  As described above, in the spool valve according to the first aspect of the present invention, by forming a control region in which the outer dimension changes at the tip of the spool, a notch is not provided at the tip of the spool. The flow rate of the port can be varied according to the operation of the spool in the axial direction.

  For this reason, since the tip of the spool can be maintained in a continuous shape over the entire circumference, the rigidity of the outer peripheral portion of the spool can be ensured.

  Therefore, it is possible to prevent the occurrence of a sliding failure due to the deformation of the spool, and to reliably prevent a malfunction due to the sliding failure.

  In the spool valve according to claim 2, the control region includes a plurality of taper portions provided in the axial direction, and an inclination angle formed by a peripheral surface of each taper portion and a central axis of the spool is set. It is set at a different angle.

  For this reason, the intended diversion characteristic can be obtained by setting the axial length of each tapered portion and the angle at each tapered portion according to the application.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a spool valve 1 according to the present embodiment, in which a nozzle portion 2 of the spool valve 1 is shown. The spool valve 1 is provided in a common rail system of a diesel engine vehicle, for example, and controls the flow rate of fuel supplied from the primary pump to the secondary pump of the common rail system.

  A circular spool housing chamber 11 is formed in the nozzle portion 2 of the spool valve 1, and the spool housing chamber 11 opens at the tip of the nozzle 2. A spool 12 is movably accommodated in the spool accommodating chamber 11, and the spool 12 is configured to be driven in the axial direction 13 by a plunger (not shown).

  The nozzle 2 is provided with an input port 21 to which fuel from the primary pump is supplied. The input port 21 includes a communication hole 22 opened in the outer peripheral surface of the nozzle 2 and the communication hole 22. It is comprised by the input groove 23 which connected. The input groove 23 extends in the circumferential direction on the inner surface of the spool housing chamber 11, and the input groove 23 is recessed in a slidable contact surface 25 with which the peripheral surface 24 of the spool 12 is slidably contacted. .

  The spool accommodating chamber 11 is opened on the tip side of the nozzle 2, and an output port 31 is configured by this opening. Thus, the fuel input from the input port 21 into the spool accommodating chamber 11 can be output to the secondary pump side via the output port 31.

  As shown in FIG. 1B, the spool 12 is formed in a bottomed cylindrical shape, and is configured such that a tip on the output port 31 side is opened. A first groove 32 and a second groove 33 extend in the circumferential direction on the peripheral surface of the spool 12 at the base end side, and the peripheral surface 24 portion on the tip side from the second groove 33 is also shown in FIG. As shown, a straight portion 42 parallel to the central axis 41 of the spool 12 is formed. The circumferential surface 24 constituting the straight portion 42 is configured to be in sliding contact with the sliding contact surface 25, and when the straight portion 42 is disposed at the position of the input groove 23, the straight portion 42 The input groove 23 is configured to be closed.

  A control region 51 that is smaller in diameter than the straight portion 42 and whose outer dimensions change toward the distal end side is set on the distal end side of the straight portion 42. Thereby, when the control area 51 is moved to the position of the input groove 23 by the operation of the spool 12 in the axial direction 13, the gap between the peripheral surface 24 and the sliding surface 25 in the control area 51. A ring-shaped gap 52 is formed in the spool housing chamber 11 so as to open the input groove 23, and the fuel supplied to the input port 21 is passed through the input port 21. It is configured to be able to flow into the spool housing chamber 11.

  The control region 51 includes a first taper portion 61 provided on the front end side from the straight portion 42, a second taper portion 62 provided on the front end side from the first taper portion 61, and the second taper portion 62. To a tip of the spool 12 and a third taper portion 63 provided between the spool 12 and the tip of the spool 12.

  Each of the tapered portions 61, 62, 63 is formed in a shape that decreases in diameter from the proximal end side toward the distal end side, and the peripheral surface 24 of each tapered portion 61, 62, 63 and the spool 12 The inclination angle formed with the central axis 41 is set to the first taper angle θ1 in the first taper portion 61. In addition, an inclination angle formed by the peripheral surface 24 at the second tapered portion 62 and the central axis 41 is set to a second taper angle θ2, and the peripheral surface 24 and the center at the third tapered portion 63 are set. The inclination angle formed with the shaft 41 is set to the third taper angle θ3, and the taper angles θ1 to θ3 are set to different angles.

  Accordingly, the gap 52 formed between the peripheral surface 24 of the spool 12 and the sliding contact surface 25 is gradually widened as the spool 12 is moved to the proximal side. The flow rate from the input port 21 can be controlled according to the operation in the axial direction 13 of the spool 12.

  And the length to the axial direction 13 of the said 1st taper part 61 and the said 2nd taper part 62 is set to the substantially same dimension, The length to the axial direction 13 of the said 3rd taper part 63 is the following. The length is set to be longer than the length of the first and second tapered portions 61 and 62. As a result, the required flow rate characteristic is obtained.

  In the present embodiment, the case where the control region 51 is configured by the tapered portions 61 to 63 having a diameter reduced from the proximal end side toward the distal end side is described as an example. However, the present invention is limited to this. For example, the cross-sectional shape may be an R shape, or a dent may be formed in the middle portion from the base end side to the tip end side.

  In the present embodiment according to the above configuration, the control region 51 is smaller in diameter at the distal end portion of the spool 12 than the straight portion 42 on the proximal end side and changes in outer dimension toward the distal end side. In this control area 51, the gap 52 formed between the peripheral surface 24 of the spool 12 and the sliding contact surface 25 with which the peripheral surface 24 is in sliding contact is set according to the set outer dimensions. Change.

  Therefore, by operating the spool 12 in the axial direction 13 with respect to the input groove 23 of the input port 21 formed on the sliding contact surface 25, the peripheral surface 24 of the spool 12 and the sliding contact surface 25 are operated. The gap 52 between them can be varied, and the flow rate through the input port 21 via the gap 52 can be varied.

  In this manner, the flow rate of the input port 21 can be controlled in accordance with the operation of the spool 12 in the axial direction 13 without providing a notch at the tip of the spool 12. For this reason, since the tip of the spool 12 can be maintained in a continuous shape over the entire circumference, the rigidity of the outer peripheral portion of the spool 12 can be ensured.

  Therefore, it is possible to prevent the occurrence of a sliding failure due to the deformation of the spool 12, and to reliably prevent a malfunction due to the sliding failure.

  The control region 51 includes first to third tapered portions 61 to 63 provided in the axial direction 13, and the circumferential surface 24 at each tapered portion 61 to 63 and the center of the spool 12. The inclination angles formed with the shaft 41 are set to different taper angles θ1 to θ3, respectively.

  For this reason, the diversion characteristic according to the objective can be obtained by setting the length of the taper portions 61 to 63 in the axial direction 13 and the taper angles θ1 to θ3 at the taper portions 61 to 63 according to the application. it can.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one embodiment of this invention, (a) is principal part sectional drawing, (b) is a perspective view of a spool. It is an enlarged view which shows the principal part of the embodiment. It is a figure which shows the conventional spool valve, (a) is principal part sectional drawing, (b) is a perspective view of a spool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spool valve 12 Spool 13 Axial direction 21 Input port 24 Circumferential surface 25 Sliding contact surface 41 Central axis 51 Control area 61 1st taper part 62 2nd taper part 63 3rd taper part (theta) 1 1st taper angle (theta) 2 2nd taper angle (theta) 3 Third taper angle

Claims (2)

In a spool valve that operates a cylindrical spool in an axial direction to open and close a port provided on a sliding contact surface on which a peripheral surface of the spool slides, and controls a flow rate from the port,
A spool valve characterized in that a control region having a smaller diameter than a proximal end portion and changing in outer dimension as it goes toward the distal end side is set at the distal end portion of the spool. A plurality of tapered portions that reduce in diameter in the axial direction from the proximal end side toward the distal end side are provided to form the control region, and the inclination angles formed by the peripheral surface of each tapered portion and the central axis of the spool are different. The spool valve according to claim 1, wherein the spool valve is set as follows.

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