JP-7855404-B2 - Liquid pump device

JP7855404B2JP 7855404 B2JP7855404 B2JP 7855404B2JP-7855404-B2

Inventors

見上裕一
荻武士
高橋潤

Assignees

株式会社ミクニ

Dates

Publication Date: 20260508
Application Date: 20220526
Priority Date: 20210828

Claims (13)

A pump unit that rotates to make the liquid flow, A housing that accommodates the pump unit and defines a passage for the liquid, The system includes a temperature sensor, which includes a bottomed cylindrical member inserted into the passage to measure the temperature of the liquid flowing through the passage, The cylindrical member is made of a resin material and includes a small diameter portion that is positioned at its tip with a gap from the inner wall surface of the passage and houses a sensor element, and a surrounding wall portion that partially surrounds the small diameter portion by being cut out in a region facing the upstream side of the passage in order to restrict liquid flowing from the upstream side of the passage, passing around the small diameter portion and to the downstream side of the passage, from colliding with the inner wall surface around the small diameter portion. A liquid pump device characterized by the following features .
The surrounding wall portion has an outer wall surface that faces the inner wall surface of the passage . The liquid pump device according to feature 1 .
The surrounding wall portion has a plurality of protrusions that project from the outer wall surface and abut against the inner wall surface of the passage in order to define a gap between the inner wall surface and the outer wall surface of the passage . The liquid pump device according to feature 2 .
A pump unit that rotates to make the liquid flow, A housing that accommodates the pump unit and defines a passage for the liquid, A motor having a drive shaft that rotates around a predetermined axis in order to rotationally drive the pump unit, A circuit board on which a control unit for controlling the drive of the motor is mounted, The system includes a temperature sensor connected to the circuit board and positioned with its tip protruding into the passage, for measuring the temperature of the liquid flowing through the passage. The housing includes a housing body that defines a joining surface to be joined to an object to be applied, a pump housing recess for housing the pump unit, a motor housing recess for housing the motor, a through passage extending parallel to the axis to form part of the passage and penetrating through to the joining surface, and a communication passage extending inclined with respect to the axis to form part of the passage and connecting the pump housing recess to the through passage, and a pump cover that is joined to the housing body to cover the pump housing recess and defines an opening for the passage of liquid. The temperature sensor is positioned such that its tip faces the intersection region of the through passage and the communication passage. A liquid pump device characterized by the following features .
The housing includes a motor cover that is joined to the housing body to cover the motor housing recess, The temperature sensor includes a bottomed cylindrical member provided in the motor cover and inserted into the through passage, and a sensor element electrically connected to the circuit board and positioned in the tip region within the cylindrical member. The liquid pump device according to feature 4 .
The cylindrical member includes a large-diameter portion that fits into the inner wall surface of the through passage, and a small-diameter portion that has a bottomed shape towards the tip of the large-diameter portion, is positioned with a gap between it and the inner wall surface of the through passage, and houses the sensor element. The small-diameter portion is located in the intersection region of the through passage and the connecting passage. The liquid pump device according to feature 5 .
The cylindrical member is made of a resin material and includes a surrounding wall portion which is curved so as to partially surround the small diameter portion by cutting out the region facing the passage. The liquid pump device according to feature 6 .
The surrounding wall portion has an outer wall surface that faces the inner wall surface of the through passage. The liquid pump device according to feature 7 .
The surrounding wall portion has a plurality of protruding portions that extend from the outer wall surface and abut against the inner wall surface of the passage in order to define a gap between the inner wall surface and the outer wall surface of the passage. The liquid pump device according to feature 8 .
The housing includes an outer cover that is joined to the motor cover to cover the circuit board located outside the motor cover, The liquid pump device according to feature 5 .
The passage in which the temperature sensor is located is a discharge passage for discharging the liquid pressurized by the pump unit. A liquid pump device according to any one of features 1 to 10 .
The pump unit includes a filter member positioned upstream of the suction port into which the liquid is drawn, The liquid pump device according to feature 11 .
The pump unit is a trochoidal type pump unit including an inner rotor and an outer rotor. The liquid pump device according to feature 12 .

Description

This invention relates to a liquid pump device that sucks in and discharges liquid, and more particularly to a liquid pump device equipped with a temperature sensor for detecting the temperature of a liquid such as hydraulic oil. A conventional liquid pump device is known to be an electric pump comprising a housing that accommodates a circuit board and a motor, a temperature sensor mounted on the circuit board located inside the housing for detecting the temperature of the hydraulic fluid, a port block located adjacent to the outside of the housing, a trochoid pump located between the port block and the housing for flowing the hydraulic fluid, a heat dissipation member located between the inner wall of the housing and the circuit board, and a heat transfer member provided on the circuit board (for example, Patent Document 1). In this electric pump, the temperature sensor detects the temperature of the hydraulic fluid via a heat transfer member, a heat dissipation member, and a housing. In the temperature sensor arrangement structure described above, the heat from the hydraulic fluid is dissipated to intervening members such as the housing and heat dissipation members along the path to the temperature sensor, making it impossible to detect the temperature of the hydraulic fluid with high accuracy. Furthermore, when a temperature sensor is installed in a liquid pump system, it is required that it be easy to assemble without increasing the size of the system. Furthermore, liquids such as hydraulic fluid have different heat transfer characteristics than gases such as air, which have lower viscosity and mass. Also, as the temperature decreases, they are more prone to stagnant flow. Therefore, when measuring the temperature of a liquid, it is necessary to consider the behavior of the liquid. Japanese Patent Publication No. 2014-125955 This is an external perspective view showing a liquid pump device according to the first embodiment of the present invention.This is an exploded perspective view of the liquid pump device according to the first embodiment, as seen from the pump cover side after disassembly.This is an exploded perspective view of the liquid pump device according to the first embodiment, as seen from the outer cover side after disassembly.This is a cross-sectional view of a liquid pump device according to the first embodiment.This is a perspective view showing the housing body of a liquid pump device according to the first embodiment.This is a perspective view showing the housing body of a liquid pump device according to the first embodiment.This is a cross-sectional view showing the housing body of a liquid pump device according to the first embodiment.This is a perspective view showing the motor cover and temperature sensor of a liquid pump device according to the first embodiment.This is a partial cross-sectional view showing the motor cover and temperature sensor of a liquid pump device according to the first embodiment.This is a schematic diagram showing the relationship between a temperature sensor placed in a passage and the flow of hydraulic fluid in a liquid pump device according to the first embodiment.This is a cross-sectional view showing the liquid pump device according to the first embodiment in a state where it is joined and attached to an object to be applied.This graph shows the detection characteristics of the temperature sensor in the liquid pump device of the present invention.This is a cross-sectional view showing the motor cover and temperature sensor of a liquid pump device according to the second embodiment.This is a cross-sectional view showing the motor cover and temperature sensor of a liquid pump device according to the third embodiment.This is a perspective view showing the temperature sensor of the liquid pump device according to the third embodiment.This is a perspective cross-sectional view showing a temperature sensor of a liquid pump device according to the third embodiment, cut by a plane including its center line.This is a cross-sectional view of a liquid pump device according to the third embodiment.This is a schematic diagram showing the relationship between a temperature sensor placed in a passage and the flow of hydraulic fluid in a liquid pump device according to the third embodiment. Embodiments of the present invention will be described below with reference to the accompanying drawings. The liquid pump device M according to the first embodiment is an electric pump device that targets hydraulic oil as the liquid, and as shown in Figures 1 to 3, it comprises a housing body 10, a pump cover 20, a motor cover 30, an outer cover 40, a pump unit 50, a motor 60, a circuit board 70, a temperature sensor 80, and a filter member 90. Here, the housing H of the liquid pump device M is composed of the housing body 10, the pump cover 20, the motor cover 30, and the outer cover 40. Furthermore, the object 1 to which the liquid pump device M is applied, as shown in Figure 11