CN-113738887-B - Electric valve

CN113738887BCN 113738887 BCN113738887 BCN 113738887BCN-113738887-B

Abstract

The invention provides an electric valve capable of ensuring the seating of a valve core when the valve is closed without using a spring with large acting force. The electric valve includes a valve body including a valve chamber, a valve port, and a valve seat, a valve shaft inserted into the valve chamber, a valve body coupled to the valve shaft, and a valve shaft driving unit for driving the valve shaft to approach or separate the valve body from the valve seat, wherein the valve body includes an inner wall forming a back pressure chamber on an opposite side of the valve port from the valve body via the valve body, a seal member is disposed between the valve shaft and the inner wall, and the electric valve includes a force generating unit for generating a force in an axial direction transmitted from the seal member to the valve body when the valve body is seated on the valve seat.

Inventors

OSHIKA Shinichiro
YAZAWA MASASHI

Assignees

株式会社不二工机

Dates

Publication Date: 20260505
Application Date: 20210311
Priority Date: 20200528

Claims (2)

1. An electrically operated valve, comprising: A valve body having a valve chamber, a valve port, and a valve seat; a valve shaft that is inserted into the valve chamber; a valve element coupled to the valve shaft, and A valve element driving unit that drives the valve shaft to approach or separate the valve element from the valve seat, The valve body includes an inner wall forming a back pressure chamber on the opposite side of the valve body to the valve port through the valve core, a sealing member is disposed between the valve shaft and the inner wall, The electric valve includes a force generating portion toward which the seal member is expanded by receiving pressure of fluid in the valve chamber and the back pressure chamber when the valve body is seated on the valve seat, and the force generating portion generates a force in an axial direction transmitted from the seal member to the valve body, The force generating portion is the valve shaft having a surface with a tapered shape, The inner wall has a cylindrical reduced diameter inner peripheral surface, a cylindrical expanded diameter inner peripheral surface, and a tapered inner peripheral surface, the seal member being located radially inward of the reduced diameter inner peripheral surface when the valve is closed, and the seal member being located radially inward of the expanded diameter inner peripheral surface when the valve is opened, the tapered inner peripheral surface connecting the reduced diameter inner peripheral surface and the expanded diameter inner peripheral surface.
2. An electrically operated valve, comprising: A valve body having a valve chamber, a valve port, and a valve seat; a valve shaft that is inserted into the valve chamber; a valve element coupled to the valve shaft, and A valve element driving unit that drives the valve shaft to approach or separate the valve element from the valve seat, The valve body includes an inner wall forming a back pressure chamber on the opposite side of the valve body to the valve port through the valve core, a sealing member is disposed between the valve shaft and the inner wall, The electric valve includes a force generating portion toward which the seal member is expanded by receiving pressure of fluid in the valve chamber and the back pressure chamber when the valve body is seated on the valve seat, and the force generating portion generates a force in an axial direction transmitted from the seal member to the valve body, The force generating portion is the inner wall having a face with a tapered shape, The inner wall has an inner conical surface, a cylindrical expanded diameter inner peripheral surface, and a tapered inner peripheral surface, the sealing member is positioned radially inward of the inner conical surface when the valve is closed, and the sealing member is positioned radially inward of the expanded diameter inner peripheral surface when the valve is opened, and the tapered inner peripheral surface connects the inner conical surface and the expanded diameter inner peripheral surface and is inclined to a side opposite to the inner conical surface.

Description

Electric valve Technical Field The present invention relates to an electrically operated valve. Background Conventionally, an electrically operated valve is used as a device for opening and closing a flow path of a fluid and controlling a flow rate, for example, in the middle of a piping system for the fluid. In such an electric valve, in order to accurately control the flow rate, a valve body is driven by a drive source such as a stepping motor attached to a valve body. Patent document 1 discloses an electrically operated valve in which a valve element is driven by a stepping motor so as to be capable of being brought into contact with and separated from a valve seat. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2019-065898 In the electric valve of patent document 1, a valve body is inserted through a guide member that divides a back pressure chamber and a valve chamber having a valve port with the valve seat, up and down, with a seal member interposed therebetween. By always communicating the back pressure chamber with the valve port, the up-and-down pressure of the valve core is equalized, the force acting on the valve core in the valve closing direction and the force acting on the valve core in the valve opening direction are balanced, and the accurate driving of the valve core is ensured. On the other hand, when closing the valve, it is necessary to maintain a state in which the valve body is in contact with the valve seat. Therefore, a spring is provided to bias the valve element in a direction toward the valve seat. Here, if the biasing force of the spring is increased, the valve element can be ensured to be seated when the valve is closed, but it is necessary to take measures against abrasion of the portion that slides while receiving the biasing force. Disclosure of Invention The invention provides an electric valve, which can ensure the seating of a valve core when the valve is closed without using a spring with large acting force. The electric valve according to the present invention includes a valve body including a valve chamber, a valve port, and a valve seat, a valve shaft inserted into the valve chamber, a valve body coupled to the valve shaft, and a valve body driving unit for driving the valve shaft to bring the valve body closer to or farther from the valve seat, wherein the valve body includes an inner wall forming a back pressure chamber on an opposite side of the valve body from the valve port with respect to the valve port, a seal member is disposed between the valve shaft and the inner wall, and the electric valve includes a force generating unit that generates a force in an axial direction transmitted from the seal member to the valve body when the valve body is seated on the valve seat. According to the electrically operated valve of the present invention, it is possible to provide an electrically operated valve capable of ensuring seating of the valve body when the valve is closed without using a spring having a large biasing force. Drawings Fig. 1 is a longitudinal sectional view showing an electrically operated valve according to a first embodiment. Fig. 2 is an enlarged cross-sectional view of a part of the motor-operated valve according to the first embodiment. Fig. 3 is an enlarged cross-sectional view of a part of the motor-operated valve according to the modification of the first embodiment. Fig. 4 is a longitudinal sectional view showing an electrically operated valve according to a second embodiment. Fig. 5 is an enlarged cross-sectional view of a part of the motor-operated valve according to the second embodiment. Fig. 6 is an enlarged cross-sectional view of a part of an electrically operated valve according to a modification of the second embodiment. Symbol description 10,10B electric valve 20,20B valve body 24,24B valve shaft 25 Fixed screw (male screw) 26 Guide bushing 27 Lower stop body 30 Rotor 31 Moving screw (female screw) 32 Valve shaft retainer 33 Pushing nut 34 Compression coil spring 35 Reset spring 36 Support ring 37 Upper stop body 40 Shell 41 Annular plate 50 Stator 60 Valve seat member 70 Valve core BC back pressure chamber VC valve chamber Detailed Description Hereinafter, embodiments of an electrically operated valve according to the present invention will be described with reference to the drawings. In the present specification, the direction from the rotor toward the valve seat is defined as the lower direction, and the opposite direction is defined as the upper direction. First embodiment Fig. 1 is a longitudinal sectional view showing an electrically operated valve 10 according to a first embodiment. The electric valve 10 for controlling the flow rate of a refrigerant (fluid) in a refrigeration cycle of an automobile or the like includes a valve shaft 24, a valve body 70 coupled to the valve shaft 24, a valve seat member 60 capable of allowing the valve body 70 to be in contact with and separated