JP2007146684A - Bearing structure of torque motor in air flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide bearing structure of a torque motor in an air flow control valve, not susceptible to an uneven flow rate and enabling highly accurate flow rate control. <P>SOLUTION: The air flow control valve 1 is constituted of a throttle body 11 and a torque motor 12 assembled to the throttle body 11. A base end part 41 of a shaft 31 disposed to a rotor 25 is rotatably supported by a casing 21 through a sleeve bearing 43. A thrust chip 52 is disposed in a small hole 51 of a recess part 42, and is abutted with a base end surface 53 of a shaft 31. An intermediate part 61 of the shaft 31 projected on a distal end side of the rotor 25 is rotatably supported by the casing 21 through a ball bearing 62. A throttle valve 81 is fixed to the distal end part of the shaft 31 so as to vary an opening are of a flow passage 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bearing structure for a torque motor in an air flow rate control valve that controls an air flow rate.

  2. Description of the Related Art Conventionally, an air flow control valve 701 is provided in an intake passage of a diesel engine vehicle, as shown in FIG. 2, so that the flow of air to the engine side can be adjusted.

  The air flow rate control valve 701 includes a torque motor 711 and a throttle body 712 to which the torque motor 711 is fixed. A throttle valve 713 provided in the throttle body 712 is connected to a shaft 714 of the torque motor 711. The air flow rate can be controlled by rotating at.

  The shaft 714 that supports the throttle valve 713 is supported by the casing 713 of the torque motor 711 through a sleeve bearing 721 at the base end, and the throttle body 712 through the sleeve bearing 722 at the center. It is supported by.

  As shown in FIG. 3, in another air flow control valve 801, the tip of a shaft 803 that supports the throttle valve 802 is supported by the throttle body 805 via a bearing 804. A central portion of the shaft 803 is supported by a casing 808 of a torque motor 807 via a resin sleeve bearing 806, and a base end portion of the shaft 803 is supported by the casing via a thrust bearing 809. 808.

  However, in such a conventional bearing structure, both of the air flow control valves 701 and 801 described above have bearings 722 and 804 having shafts 714 and 803 provided in the throttle bodies 712 and 805, and a torque motor 711. , 807 are supported by bearings 722, 806, and 809 provided in casings 713 and 808, respectively.

  For this reason, when the torque motors 711 and 807 are assembled to the throttle valves 712 and 805 to support the shafts 714 and 803, it is difficult to obtain accuracy, and control by the throttle valves 713 and 802 provided on the shafts 714 and 803 is performed. It was easy for the amount to vary.

  The present invention has been made in view of such a conventional problem, and provides a bearing structure for a torque motor in an air flow rate control valve that is less likely to cause unevenness in flow rate and enables highly accurate flow rate control. It is intended to do.

  In order to solve the above problems, in the bearing structure of the torque motor in the air flow control valve according to claim 1 of the present invention, the torque motor is assembled to the throttle body, and the throttle valve provided in the throttle body is connected to the torque motor. In the bearing structure of the torque motor in the air flow control valve that controls the flow rate in the throttle body by rotating with the extended shaft, the bearings that support the shaft are set at two locations, and both bearings are It was supported on the casing of the torque motor.

  That is, the shaft extended from the torque motor assembled to the throttle body has two bearings for supporting the shaft, and both bearings are supported by the casing of the torque motor.

  For this reason, bearings for supporting the shaft are arranged separately on the throttle body side and the casing side, and when the torque motor is assembled to the throttle body, the throttle body side bearing and the casing side bearing are Compared with the prior art that had to be arranged on the same axis, the coaxiality of both bearings can be ensured only on the torque motor side. As a result, shaft misalignment or the like due to assembly accuracy is prevented.

  Further, in the bearing structure of the torque motor in the air flow control valve according to claim 2, one of the bearings is constituted by a ball bearing, and the other of the bearings is a sleeve bearing for supporting the shaft from an outer peripheral portion. Consists of.

  That is, the shaft can be prevented from rattling in the thrust direction by a ball bearing constituting one of the bearings. Further, the sleeve bearing that constitutes the bearing suppresses rattling in the radial direction.

  Furthermore, in the bearing structure of the torque motor in the air flow rate control valve according to claim 3, the biasing means for biasing the shaft toward the base end side is provided, and the biasing means is in contact with the base end of the shaft. A thrust chip that receives the urging force of is provided in the casing.

  Thereby, the shaft is supported in a state where the base end is pressed against the thrust tip.

  As described above, in the bearing structure of the torque motor in the air flow control valve according to claim 1 of the present invention, the coaxiality of both bearings supporting the shaft can be ensured only on the torque motor side.

  For this reason, it is possible to prevent shaft misalignment or the like due to assembly accuracy as compared with the conventional configuration in which the bearing supporting the shaft is arranged separately on the throttle body side and the casing side. As a result, flow rate unevenness due to the displacement of the throttle valve provided on the shaft can be prevented, and highly accurate flow rate control can be performed.

  Further, in the bearing structure of the torque motor in the air flow rate control valve according to claim 2, the ball bearing constituting one of the bearings can prevent the shaft from rattling in the thrust direction. Further, the sleeve bearing constituting the bearing can prevent the shaft from rattling in the radial direction.

  Thereby, the behavior of the throttle valve rotated by the shaft can be suppressed, and more advanced flow rate control can be performed.

  In addition, the cost can be reduced as compared with the case where both the bearings are constituted by expensive ball bearings.

  Furthermore, in the bearing structure of the torque motor in the air flow rate control valve according to the third aspect, the shaft can be supported in a state where the base end of the shaft is pressed against the thrust tip.

  Thereby, shakiness of the shaft in the thrust direction can be suppressed, and more advanced flow rate control can be performed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an air flow rate control valve having a torque motor bearing structure according to the present embodiment. The air flow rate control valve 1 is provided in an intake passage of a diesel engine vehicle and is connected to an engine side. It controls the flow of air.

  The air flow rate control valve 1 is constituted by a throttle body 11 disposed on the intake passage and a torque motor 12 assembled to the throttle body 11. A cylinder portion 13 formed on the throttle body 11 Is formed with a flow passage 14 constituting a part of the intake passage.

  A magnetic circuit 22 is configured in the casing 21 of the torque motor 12, and the magnetic circuit 22 includes a solenoid 23 and a pair of magnetic delivery portions 24 and 24 excited by the solenoid 23. Yes. A rotor 25 is disposed between the two magnetic transfer portions 24, 24, and a magnet 27 is provided on the outer peripheral portion of the core 26 constituting the rotor 25. As a result, the magnet 27 receives the magnetic force from the magnetic delivery portions 24, 24 excited by the solenoid 23, so that the rotor 25 rotates according to the energized state of the solenoid 23. Yes.

  A shaft 31 is provided at the rotation center C of the rotor 25, and the shaft 31 is rotatably supported by the casing 21 of the torque motor 12 through two bearings.

  That is, the base end portion 41 of the shaft 31 protruding toward the base end side of the rotor 25 is inserted into the recess 42 provided in the casing 21, and the base end portion 41 is external to the base end portion 41. The casing 21 is supported by a sleeve bearing 43 that is fitted and fitted in the recess 42. The sleeve bearing 43 constituting one of the bearings is made of a sintered alloy formed in a cylindrical shape, and the sleeve bearing 43 is impregnated with oil. Thereby, this sleeve bearing 43 is comprised so that the said shaft 31 may be rotatably supported in the state fitted on the outer peripheral part of the said shaft 31. As shown in FIG.

  A bottomed small hole 51 is provided in the inner surface of the recess 42, and a resin-made thrust chip 52 formed in a cylindrical shape is accommodated in the small hole 51. The thrust tip 52 is set to have a length protruding from the small hole 51 and is configured to abut on the proximal end surface 53 of the shaft 31 at the rotation center C.

  The oil that has oozed out from the sleeve bearing 43 is configured to be stored in the recess 42, and the oil is used as lubricating oil for the base end surface 53 of the shaft 31 and the thrust tip 52. Is done.

  An inner ring 63 of a ball bearing 62 constituting the other bearing is fitted on a midway part 61 of the shaft 31 protruding to the tip side of the rotor 25, and the outer ring 64 of the ball bearing 62 is attached to the rotor 25. It is fitted in the rotor accommodating chamber 65 of the accommodated casing 21. Thereby, the midway part 61 of the shaft 31 is rotatably supported by the casing 21 via the ball bearing 62.

  A disc spring 73 as an urging means is disposed between the outer ring 64 of the ball bearing 62 and a lid portion 72 provided on the front end surface 71 of the casing 21. Is urged toward the base end side by the spring force of the disc spring 73. A protruding portion 74 protruding from the core 26 of the rotor 25 is in contact with the inner ring 63 of the ball bearing 62, and a spring force by the disc spring 73 is applied to the rotor 25 via the ball bearing 62. Are granted. As a result, the shaft 31 fixed to the rotor 25 is biased toward the base end side, and the base end surface 53 of the shaft 31 is pressed against the thrust tip 52.

  The tip portion of the shaft 31 extending from the torque motor 12 is configured to pass through the cylindrical portion 13 of the throttle body 11 and extend into the passage 14. A disc-shaped throttle valve 81 that changes the opening area of the flow passage 14 is fixed to the tip portion.

  Accordingly, the shaft 31 is rotated by the torque motor 12 and the throttle valve 81 provided on the shaft 31 is tilted so that the flow rate of air passing through the passage 14 can be controlled. It is configured.

  In the present embodiment according to the above configuration, the shaft 31 extending from the torque motor 12 assembled to the throttle body 11 has two bearings for supporting the shaft 31, and both bearings are The torque motor 12 is supported by the casing 21.

  For this reason, bearings that support the shaft 31 are arranged separately on the throttle body 11 side and the casing 21 side, and when the torque motor 12 is assembled to the throttle body 11, the bearing on the throttle body 11 side Compared with the conventional structure in which the bearing on the casing 21 side must be arranged coaxially, the coaxiality of both bearings can be ensured only by the structure on the torque motor 12 side.

  Further, it is possible to prevent the shaft 31 from being displaced due to the assembly accuracy between the throttle body 11 and the casing 21. Thereby, flow rate unevenness due to the displacement of the throttle valve 81 provided on the shaft 31 can be prevented, and highly accurate flow rate control can be performed.

  One of the bearings is constituted by a ball bearing 62, and the other of the bearings is constituted by a sleeve bearing 43. For this reason, the ball bearing 62 can prevent the shaft 31 from rattling in the thrust direction. Further, the sleeve bearing 43 can prevent the shaft 31 from rattling in the radial direction.

  As a result, the behavior of the throttle valve 81 rotated by the shaft 31 can be suppressed, and more advanced flow rate control can be performed, and the throttle valve 81 is rubbed against the inner wall of the passage 14. Can be prevented.

  In addition, the cost can be reduced as compared with the case where both the bearings are constituted by expensive ball bearings 62.

  The shaft 31 is supported in a state where the base end surface 53 is pressed against the resin-made thrust chip 52.

  For this reason, shakiness of the shaft 31 in the thrust direction can be suppressed, and more advanced flow rate control can be performed.

It is sectional drawing which shows one embodiment of this invention. It is sectional drawing which shows the conventional air flow control valve. It is sectional drawing which shows the other conventional air flow control valve.

Explanation of symbols

1 Air Flow Control Valve 11 Throttle Body 12 Torque Motor 21 Casing 31 Shaft 43 Sleeve Bearing 52 Thrust Tip 62 Ball Bearing 73 Belleville Spring 81 Throttle Valve

Claims (3)

A torque motor is assembled to the throttle body, and a throttle valve provided on the throttle body is rotated by a shaft extending from the torque motor to control the torque motor in the air flow control valve that controls the flow rate in the throttle body. In the bearing structure,
2. A bearing structure for a torque motor in an air flow control valve, wherein bearings for supporting the shaft are set at two locations, and both bearings are supported by a casing of the torque motor.   2. The torque in the air flow control valve according to claim 1, wherein one of the bearings is constituted by a ball bearing, and the other of the bearings is constituted by a sleeve bearing that supports the shaft from an outer peripheral portion. Motor bearing structure. An urging means for urging the shaft toward the base end side is provided, and a thrust tip that contacts the basal end of the shaft and receives the urging force by the urging means is provided on the casing. The bearing structure of the torque motor in the air flow rate control valve according to claim 1 or 2.

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