JP2010125948A - Electric power-steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent enlargement and reduction of a rubber boot due to a change of temperature in a motor housing of an electric motor and to improve durability of the rubber boot in an electric power-steering device. <P>SOLUTION: In the electric power-steering device, a motor housing 12C of an electric motor 20 is provided in a gear box, a control unit performing drive control of the electric motor 20 is connected through a feeding cable 60 to the electric motor 20 in the motor housing 12C, the electric motor 20 is driven corresponding to a steering torque applied to a steering wheel, and an output of the electric motor 20 is transmitted to a rack shaft 13 as a steering assist force. Further, a vent passage communicating a communication space 80 for the gear box, the motor housing 12C and the rubber boot with the control unit is provided within a cross-section of the cable 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric power steering apparatus.

  As an electric power steering device, as described in Patent Document 1, a rack shaft that reciprocates in conjunction with rotation of a steering wheel is supported by a gear box, and left and right wheels can be steered to the rack shaft via left and right tie rods. Connect the rubber boots to the gear box and the left and right tie rods, and connect them to each other. The motor housing of the electric motor is installed in the gear box, and the control unit that controls the drive of the electric motor is connected to the electric motor in the motor housing by the power supply cable. There is one that connects and drives the electric motor according to the steering torque applied to the steering wheel, and transmits the output of the electric motor to the rack shaft as a steering assist force.

  In the electric power steering apparatus described in Patent Document 1, a sealed motor housing of an electric motor is attached to a case of a reduction gear in a gear box. For this reason, if the gas in the motor housing contracts due to the temperature drop in the motor housing due to heat generation due to driving of the electric motor or heat dissipation during stoppage, oil and dust in the case of the speed reducer will be removed from the outer clearance of the output shaft of the electric motor. There is a risk of entering the motor housing via the.

Therefore, in the electric power steering device described in Patent Document 1, the sealed motor housing of the electric motor is directly connected to the rubber boot, and the gas in the motor housing contracts due to the temperature drop in the motor housing of the electric motor. At that time, the gas in the rubber boot was allowed to enter the motor housing. This prevents oil or dust in the case of the reduction gear from entering the motor housing through the outer peripheral clearance of the output shaft of the electric motor.
Reality 5-42950

  In the electric power steering apparatus described in Patent Document 1, the motor housing of the electric motor is communicated with the rubber boot. Therefore, when the gas in the motor housing expands due to the temperature rise in the motor housing of the electric motor, the gas in the motor housing enters the rubber boot, and the gas pressure in the rubber boot increases. On the other hand, when the gas in the motor housing contracts due to the temperature drop in the motor housing of the electric motor, the gas in the rubber boot enters the motor housing and the gas pressure in the rubber boot is reduced.

  FIG. 10 shows the gear box 1, the rack shaft 2, the tie rod 3, and the rubber boot 4, (A) shows a state in which the rubber boot 4 is expanded by increasing the gas pressure P, and (B) shows the rubber boot 4 having the gas pressure P The state contracted by the reduced pressure is shown. The expanded rubber boot 4 hits the surrounding structure 5, and if the rack shaft 2 strokes as it is, the outer surface of the rubber boot 4 directly contacts the structure 5 and the rubber boot 4 may be broken. The contracted rubber boot 4 hits the internal ball joint 3A, and if the rack shaft 2 strokes as it is, the inner surface of the rubber boot 4 is scraped to the corner of the ball joint 3A, and the rubber boot 4 may be broken.

  An object of the present invention is to avoid the expansion and contraction of a rubber boot due to a temperature change in a motor housing of an electric motor and to improve the durability of the rubber boot in an electric power steering apparatus.

  According to the first aspect of the present invention, a rack shaft that reciprocates in conjunction with rotation of a steering wheel is supported by a gear box, and left and right wheels are connected to the rack shaft via left and right tie rods so as to be steerable. A rubber boot is connected to each of the tie rods, and a motor housing of the electric motor is provided in the gear box. A control unit for driving and controlling the electric motor is connected to the electric motor in the motor housing by a power supply cable, and the electric motor is steered. In the electric power steering apparatus that drives according to the steering torque applied to the wheel and transmits the output of the electric motor as a steering assist force to the rack shaft, the gear box, the motor housing, and the rubber boot are included in the cross section of the cable. Ventilation path communicating with the control unit through the sealed communication space Those digits.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first connector provided on the electric wire cladding tube of the cable is fitted into the second connector provided on the motor housing, and the first terminal of the first connector and the first connector When the second terminal of the two connectors can be connected in the terminal connection space formed in the fitting portion of both connectors, the air passage of the cable is provided with the air passage provided in the tube of the wire cladding tube, and the first connector. The first connector air passage for connecting the air passage in the wire cladding tube to the terminal connection space, and the terminal connector connecting the three communication spaces of the gear box, the motor housing, and the rubber boot provided for the second connector. The second connector vent passage communicates with the space.

(Claim 1)
(a) In the cross section of the power supply cable connected to the control unit and the electric motor in the motor housing, an air passage that communicates the control space with a communication space sealed by the gear box, the motor housing, and the rubber boot is provided.

  Therefore, when the gas in the motor housing expands due to the temperature rise in the motor housing of the electric motor, the gas in the motor housing is immediately discharged to the control unit through the air passage of the cable. Therefore, even if the motor housing communicates with the gear box and the rubber boot, the gas in the motor housing does not enter the rubber boot, and the gas pressure in the rubber boot does not increase and the rubber boot does not expand. The outer surface of the rubber boot hits the surrounding structure and there is no risk of damage due to contact.

  Further, when the gas in the motor housing contracts due to the temperature drop in the motor housing of the electric motor, the gas on the control unit side is immediately sucked into the motor housing through the air passage of the cable. Therefore, even if the motor housing communicates with the gear box and the rubber boot, the gas in the rubber boot does not enter the motor housing, and the gas pressure in the rubber boot is reduced and the rubber boot does not contract. The inner surface of the rubber boot hits the universal joint of the tie rod and there is no risk of damage.

(Claim 2)
(b) When forming the air passage that connects the three communication spaces of the gear box, the motor housing, and the rubber boot of the above-mentioned (a) to the control unit, the air passage of the cable is provided in the pipe of the wire cladding tube. A communication path between the first connector and the first connector for communicating the ventilation path in the wire cladding tube with the terminal connection space; and a gear box, a motor housing and a rubber boot provided in the second connector. The space was made up of the second connector vent passage communicating with the terminal connection space. Therefore, when the cable is provided with the first connector on the wire cladding tube and the second connector is provided on the motor housing, the communication space of the three of the gear box, the motor housing, and the rubber boot is communicated with the control unit in the cross section of the cable. A ventilation path can be formed.

  1 is a cross-sectional view showing an electric power steering apparatus according to a first embodiment, FIG. 2 is a cross-sectional view showing a main part of FIG. 1, and FIG. 3 is a cross-sectional view showing a fitting structure of a first connector and a second connector of a cable, 4 is a cross-sectional view showing a cross section of the cable, FIG. 5 is a cross-sectional view showing the electric power steering apparatus of the second embodiment, FIG. 6 is a cross-sectional view showing the main part of FIG. 5, and FIG. FIG. 8 is a sectional view showing a cross section of the cable, FIG. 9 is a sectional view showing another example of the cable, and FIG. 10 is a schematic sectional view showing a deformed state of the rubber boot. is there.

Example 1 (FIGS. 1 to 4)
As shown in FIGS. 1 and 2, the electric power steering apparatus 10 supports the input shaft 11 to which the steering wheel is joined to the first gear housing 12A of the gear box 12, and is integrated with the first gear housing 12A of the gear box 12. The motor housing 12C of the electric motor 20 is provided integrally with the second gear housing 12B. A part of the gear box 12 is a motor housing 12C.

  In the first gear housing 12A of the gear box 12, an output shaft (not shown) is connected to the input shaft 11 via a torsion bar, and a steering torque detection device (not shown) is assembled between the input shaft 11 and the output shaft. Attached. The rack shaft 13 is supported by the second gear housing 12B and the motor housing 12C of the gear box 12, and the rack teeth of the rack shaft 13 mesh with the pinion of the output shaft in the gear box 12 to form a rack and pinion mechanism. Then, it reciprocates linearly in conjunction with the rotation of the steering wheel.

  Left and right tie rods 14 are connected to both ends of the rack shaft 13 projecting from both ends of the gear box 12 (second gear housing 12B and motor housing 12C) via universal joints 14A. The wheels are connected to be steerable.

  Rubber boots 15 are air-tightly connected to both ends of the gear box 12 (second gear housing 12B and motor housing 12C) and the left and right tie rods 14, respectively. The internal spaces of the left and right rubber boots 15 are communicated with each other by an air passage provided in the axial direction of the rack shaft 13 and allow the rubber boots 15 to expand and contract.

  The electric motor 20 includes a stator 21 that is fixed to the inner periphery of the motor housing 12 </ b> C of the gear box 12, a rotor 22 that is rotatably disposed on the inner periphery side of the stator 21, and a rotor 22 with respect to the stator 21. And a resolver 23 for detecting the rotational position.

  The stator 21 is configured by attaching a resin bobbin 21B to a core 21A made of a silicon steel plate, and winding U-phase, V-phase, and W-phase motor coils 21C around the resin bobbin 21B.

  The rotor 22 has a hollow rotary shaft 22A disposed around the rack shaft 13, and a ball nut 32 is fixed to one end of the rotary shaft 22A. The rotor 22 (rotating shaft 22A, ball nut 32) is supported on the gear box 12 (second gear housing 12B and motor housing 12C) by bearings 24 and 25. A rotor magnet 22B is positioned and fixed in the circumferential direction at a position facing the stator 21 on the outer periphery of the rotating shaft 22A.

  In the electric power steering apparatus 10, a ball screw 31 is provided on the rack shaft 13, and a ball nut 32 that meshes with the ball screw 31 is provided at one end of the rotary shaft 22 </ b> A. A steel ball 33 is held between the screw groove of the ball screw 31 and the ball nut 32, and the rotation of the ball nut 32 is converted into a linear movement of the rack shaft 13 by the ball screw 31.

  The resolver 23 includes a resolver stator 41 assembled at a constant circumferential position with respect to the stator 21 and a resolver rotor 42 assembled at a constant circumferential position with respect to the rotor 22. Based on the change in reluctance generated between the resolver stator 41 and the resolver rotor 42, the rotational position of the rotary shaft 22A is detected.

  In the electric power steering apparatus 10, an external control unit (ECU) 50 applies predetermined values to the U-phase, V-phase, and W-phase coils 21C of the stator 21 in accordance with the rotational position of the rotation shaft 22A detected by the resolver 23. Current is supplied and the motor 20 is driven and controlled. That is, the control unit 50 is connected to the stator 21 of the motor 20 in the motor housing 12C and the resolver stator 41 of the resolver 23 by the power supply cables 60 and 70, and the motor 20 is driven according to the steering torque applied to the steering wheel. The output of the motor 20 is transmitted to the rack shaft 13 as a steering assist force.

  In the electric power steering apparatus 10, the first connector 62 provided at one end of the electric wire cladding 61 of the cable 60 is detachably fitted to the second connector 26 provided in the motor housing 12C, and as shown in FIG. The U-phase, V-phase, and W-phase first terminals 63 of the connector 62 and the U-phase, V-phase, and W-phase second terminals 27 of the second connector 26 are fitted to the fitting portions of the connectors 62 and 26. Connect in the formed terminal connection space A. Each first terminal 63 of the first connector 62 is connected to one end of each of the three power supply wires 64 covered with the wire cladding tube 61. Each second terminal 27 of the second connector 26 is connected to each coil 21 </ b> C via a bus ring assembly 28. The other end of the electric wire cladding 61 is fitted into the case 51 of the control unit 50, and each of the other ends of the three power supply lines 64 is connected to the control board in the case 51.

  However, the electric power steering apparatus 10 communicates the gear housings 12A and 12B, the motor housing 12C, and the left and right boots 15 of the gear box 12 with each other through a gap such as a bearing around the rack shaft 13. And in order to avoid the expansion / contraction of the boot 15 by the temperature change of the internal space of the motor housing 12C, it has the following structures.

  That is, the electric power steering apparatus 10 has a ventilation path 65 that communicates the closed communication space 80 of the gear housings 12A and 12B, the motor housing 12C, and the left and right boots 15 of the gear box 12 to the control unit 50 side. It is provided in the cross section of the cable 60. Specifically, as shown in FIG. 4, the cable 60 is composed of an outer layer 61A of the electric wire cladding 61, an inner layer 61B covered by the outer layer 61A, and three feeders 64 covered by the inner layer 61B. A space in which the outer layer 61A is continuously formed along the entire length of a part of the periphery of the inner layer 61B is referred to as an air passage 65.

  Here, the control unit 50 of the present embodiment is disposed in the passenger compartment, and the airtightness of the case 51 is not high, and the case 51 is opened to the atmosphere as it is. When the control unit 50 is disposed outside the passenger compartment, the case 51 includes a filter that allows only air to pass through.

  Further, in the electric power steering apparatus 10, the first connector 62 includes a first connector air passage 65A that communicates the air passage 65 of the cable 60 with the terminal connection space A, and the second connector 26 communicates the communication space 80 with the terminal. A second connector vent passage 65B communicating with the connection space A is provided.

  Note that the air passage 65 (65A, 65B) of the cable 60 is directly connected to the communication space 80 of the gear housing 12 including the gear housings 12A, 12B, the motor housing 12C, and the left and right boots 15, particularly the inner space of the motor housing 12C. Communicate with. At this time, the flow passage area of the air passage 65 (65A, 65B) is provided in the gear box 12 or the like so that the gear housing 12A, 12B of the gear box 12, the motor housing 12C, and the left and right boots 15 communicate with each other. It is sufficiently larger than the clearance of the bearing around the rack shaft 13.

According to the present embodiment, the following operational effects can be obtained.
(a) The three communication spaces 80 of the gear box 12, the motor housing 12C, and the rubber boot 15 are communicated to the control unit 50 side in the cross section of the power supply cable 60 that connects the control unit 50 to the electric motor 20 in the motor housing 12C. An air passage 65 is provided.

  Therefore, when the gas in the motor housing 12C expands due to the temperature rise in the motor housing 12C of the electric motor 20, the gas in the motor housing 12C is immediately discharged from the control unit 50 side via the air passage 65 of the cable 60. The Therefore, even if the motor housing 12C communicates with the gear box 12 and the rubber boot 15, the gas in the motor housing 12C does not enter the rubber boot 15, and the gas pressure in the rubber boot 15 increases and the rubber boot 15 There is no expansion. The outer surface of the rubber boot 15 hits the surrounding structure and there is no risk of damage.

  Further, when the gas in the motor housing 12C contracts due to the temperature drop in the motor housing 12C of the electric motor 20, the gas from the control unit 50 side is immediately sucked into the motor housing 12C through the air passage 65 of the cable 60. Is done. Therefore, even if the motor housing 12C communicates with the gear box 12 and the rubber boot 15, the gas in the rubber boot 15 does not enter the motor housing 12C, the gas pressure in the rubber boot 15 is reduced, and the rubber boot 15 There is no contraction. The inner surface of the rubber boot 15 hits the universal joint 14A of the tie rod 14, and there is no possibility of damage.

  (b) When forming the air passage 65 that connects the three communication spaces 80 of the gear box 12, the motor housing 12C, and the rubber boot 15 of the above-mentioned (a) to the control unit 50, the air passage 65 of the cable 60 is covered with the electric wire. An air passage 65 provided in the pipe 61, a first in-connector air passage 65A provided in the first connector 62 and communicating the air passage 65 in the wire sheathing pipe 61 with the terminal connection space A, and a second connector. 26, the three communication spaces 80 of the gear box 12, the motor housing 12C, and the rubber boot 15 are made up of the second connector vent passage 65B communicating with the terminal connection space A. Therefore, when the cable 60 is provided with the first connector 62 in the electric wire cladding 61 and the second connector 26 is provided in the motor housing 12C, the gear box 12, the motor housing 12C, and the rubber boot 15 are within the cross section of the power supply cable 60. The air passage 65 that communicates the communication space 80 of the three parties to the control unit 50 side can be easily formed.

  In addition, you may provide the ventilation path of this invention in the cross section of the cable 70 for the detection signal wire | line of the resolver 23. FIG.

Example 2 (FIGS. 5 to 8)
As shown in FIGS. 5 and 6, the electric power steering device 110 supports an input shaft 111 to which a steering wheel is coupled to a first gear housing 112 </ b> A of a gear box 112 and gears motor housings 120 </ b> A and 120 </ b> B of the electric motor 120. The box 112 is integrally attached to the first gear housing 112A.

  In the first gear housing 112A of the gear box 112, the output shaft 111A is connected to the input shaft 111 via a torsion bar, and a steering torque detection device (not shown) is assembled between the input shaft 111 and the output shaft. . A rack shaft 113 is supported on the second gear housing 112B integrated with the first gear housing 112A of the gear box 112, and the rack teeth of the rack shaft 113 mesh with the pinion of the output shaft 111A in the gear box 112, thereby An and pinion mechanism is formed and reciprocates linearly in conjunction with the rotation of the steering wheel.

  The cylindrical body 114B and the cylindrical body 114B can be attached to the outside of the cylindrical body 114B by bolts 114A at the left and right positions of the intermediate part of the rack shaft 113 facing the intermediate window of the gear box 112 (second gear housing 112B). The left and right tie rods 114 are connected via a joint 114C, and the left and right wheels are connected to each tie rod 114 so as to be steerable.

  Rubber boots 115 are connected and stretched to both sides of the intermediate window portion of the gear box 112 (second gear housing 112B) and both ends of the cylindrical body 114B to which the left and right tie rods 114 are connected. Yes.

  The rotating shaft 121 of the electric motor 120 is supported by the motor housings 120A and 120B by bearings 124 and 123. An assist shaft 125 is coupled to the rotating shaft 121 of the electric motor 120 via a torque limiter 124, and the assist shaft 125 is supported on the motor housing 112 </ b> A by bearings 126 and 127. The assist shaft 125 is integrally provided with a worm gear 128, and a worm wheel 129 that meshes with the worm gear 128 is fixed to an intermediate portion of the output shaft 111A.

  The electric motor 120 includes a stator 131 that is fixed to the inner periphery of the motor housing 120 </ b> B, and a rotor 132 that is disposed on the inner periphery side of the stator 131 and is fixed to the rotating shaft 121. The rotor 132 includes an amateur core 132A and a commutator 132B provided on the outer periphery of the rotating shaft 121. The electric motor 120 includes two brushes 133 that are held by the motor housing 120 </ b> A and come into contact with the commutator 132 </ b> B of the rotor 132.

  The electric power steering device 110 supplies a predetermined current to the brush 133 by an external control unit (ECU) 140 to drive and control the electric motor 120. That is, the control unit 140 is connected to the brush 133 of the motor 120 in the motor housing 120 </ b> A by the cable 150, the motor 120 is driven according to the steering torque applied to the steering wheel, and the output of the motor 120 is steered to the rack shaft 113. Tell as assist power.

  In the electric power steering apparatus 110, the first connector 152 provided at one end of the electric wire cladding 151 of the control unit 140 is detachably fitted to the second connector 134 provided in the motor housing 120A. As shown in FIG. The two first terminals 153 of the one connector 152 and the two second terminals 135 of the second connector 134 are connected in the terminal connection space A formed in the fitting portions of the connectors 152 and 134. Each first terminal 153 of the first connector 152 is connected to one end of each of the two power supply lines 154 covered by the wire cladding tube 151. Each second terminal 135 of the second connector 134 is connected to each brush 133 via a pigtail. The other end of the wire cladding tube 151 is fitted into the case 141 of the control unit 140, and each of the other ends of the two power supply lines 154 is connected to a control board in the case 141.

  However, in the electric power steering apparatus 110, the gear housing 112A, 112B of the gear box 112, the motor housings 120A, 120B, and the left and right boots 115 communicate with each other through a gap such as a bearing around the rack shaft 113. . And in order to avoid the expansion / contraction of the boot 115 by the temperature change of motor housing 120A, 120B, it has the following structures.

  That is, the electric power steering device 110 has a ventilation path 155 that communicates the closed communication space 160 of the gear housing 112A, 112B of the gear box 112, the motor housing 120A, 120B, and the left and right boots 115 to the control unit 140. Provided in the cross section of the cable 150. Specifically, as shown in FIG. 8, the cable 150 is composed of an outer layer 151A of a wire cladding tube 151, an inner layer 151B covered by the outer layer 151A, and two power supply lines 154 covered by the inner layer 151B. A space in which the outer layer 151A is continuously formed along the entire length of a part of the periphery of the inner layer 151B is defined as an air passage 155.

  Here, the control unit 140 according to the present embodiment is disposed in the passenger compartment, and the airtightness of the case 141 is not so high, and the case 141 is opened to the atmosphere as it is. When the control unit 140 is disposed outside the vehicle compartment, the case 141 may include a filter that allows only air to pass through.

  Furthermore, the electric power steering apparatus 110 includes a first connector air passage 155A in which the first connector 152 communicates the air passage 155 of the cable 150 to the terminal connection space A, and the second connector 134 connects the communication space 160 to the terminal. A second connector vent passage 155B communicating with the connection space A is provided.

  Note that the air passage 155 (155A, 155B) of the cable 150 is provided for the three communication spaces 160 of the gear housings 112A and 112B, the motor housings 120A and 120B and the left and right boots 115 of the gear box 112, particularly the motor housings 120A and 120B. Direct communication with the internal space. At this time, the flow passage area of the ventilation path 155 (155A, 155B) is such that the gear housing 112A, 112B of the gear box 112, the motor housing 120A, 120B, and the left and right boots 115 communicate with each other. It is sufficiently larger than a communication gap such as a bearing around the rack shaft 113 provided in the rack.

According to the present embodiment, the following operational effects can be obtained.
(a) In the cross section of the cable 150 connected from the control unit 140 to the electric motor 120 in the motor housing 120A, 120B, the communication space 160 of the three members of the gear box 112, the motor housing 120A, 120B, and the rubber boot 115 is formed in the control unit 140. An air passage 155 communicating with the air is provided.

  Therefore, when the gas in the motor housings 120A and 120B expands due to the temperature rise in the motor housings 120A and 120B of the electric motor 120, the gas in the motor housings 120A and 120B is immediately controlled via the air passage 155 of the cable 150. It is discharged to the unit 140 side. Therefore, even if the motor housings 120A and 120B communicate with the gear box 112 and the rubber boot 115, the gas in the motor housings 120A and 120B does not enter the rubber boot 115, and the gas pressure in the rubber boot 115 increases. Thus, the rubber boot 115 does not expand. The outer surface of the rubber boot 115 hits the surrounding structure and there is no risk of damage.

  Further, when the gas in the motor housings 120A and 120B contracts due to the temperature drop in the motor housings 120A and 120B of the electric motor 120, the gas immediately flows from the control unit 140 side via the air passage 155 of the cable 150 to the motor housing 120A. , 120B. Therefore, even if the motor housings 120A and 120B communicate with the gear box 112 and the rubber boot 115, the gas in the rubber boot 115 does not enter the motor housings 120A and 120B, and the gas pressure in the rubber boot 115 is reduced. Thus, the rubber boot 115 does not shrink. The inner surface of the rubber boot 115 hits the universal joint 114C of the tie rod 114, and there is no risk of damage.

  (b) When forming the air passage 155 that connects the three communication spaces 160 of the gear box 112, the motor housings 120A and 120B, and the rubber boot 115 of the above-mentioned (a) to the control unit 140, the air passage 155 of the cable 150 is An air passage 155 provided in the tube of the electric wire cladding tube 151, an air passage 155A in the first connector provided in the first connector 152 and communicating the air passage 155 in the electric wire cladding tube 151 with the terminal connection space A; The three communication spaces 160 provided on the two connectors 134, which are the gear box 112, the motor housings 120A and 120B, and the rubber boots 115, are composed of a second connector air passage 155B communicating with the terminal connection space A. Therefore, when the cable 150 is provided with the first connector 152 in the wire cladding tube 151 and the second connector 134 is provided in the motor housings 120A and 120B, the gear box 112 and the motor housings 120A and 120B are included in the cross section of the cable 150. The ventilation path 155 that communicates the communication space 160 of the three members of the rubber boot 115 with the control unit 140 can be easily formed using a power supply cable.

  The cable shown in FIG. 9 can be used as the cable used in the present invention. A cable 200 shown in FIG. 9 covers a plurality of power supply lines (or signal lines) 202 inside an electric wire cladding 201 formed of a single layer, and the gap between the strands of each power supply line 202 is defined as a ventilation path of the present invention. 203.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

FIG. 1 is a cross-sectional view showing an electric power steering apparatus according to a first embodiment. FIG. 2 is a cross-sectional view showing a main part of FIG. FIG. 3 is a cross-sectional view showing the fitting structure of the first connector and the second connector of the cable. FIG. 4 is a cross-sectional view showing a cross section of the cable. FIG. 5 is a cross-sectional view showing the electric power steering apparatus of the second embodiment. 6 is a cross-sectional view showing a main part of FIG. FIG. 7 is a sectional view showing the fitting structure of the first connector and the second connector of the cable. FIG. 8 is a sectional view showing a transverse section of the cable. FIG. 9 is a cross-sectional view showing another example of the cable. FIG. 10 is a schematic cross-sectional view showing a deformed state of the rubber boot.

Explanation of symbols

10, 110 Electric power steering device 12, 112 Gear box 12C Motor housing 13, 113 Rack shaft 14, 114 Tie rod 15, 115 Rubber boot 20, 120 Electric motor 120A, 120B Motor housing 26, 134 Second connector 27, 135 Second terminal 50, 140 Control unit 60, 70, 150 Cable 61, 151 Wire sheath tube 62, 152 First connector 63, 153 First terminal 64, 154 Feed line 65, 65A, 65B, 155, 155A, 155B Ventilation path 80, 160 Communication space

Claims (2)

The rack shaft, which reciprocates in conjunction with the rotation of the steering wheel, is supported by the gear box, and the left and right wheels are connected to the rack shaft via the left and right tie rods so that the left and right tie rods can be steered. Concatenated and handed over,
The motor housing of the electric motor is provided in the gear box, and is connected to the electric motor in the motor housing by a power feeding cable from the control unit that controls the driving of the electric motor, and the electric motor is driven according to the steering torque applied to the steering wheel. In the electric power steering device that transmits the output of the electric motor as a steering assist force to the rack shaft,
An electric power steering apparatus characterized in that an air passage communicating with a control unit is provided in a communication space sealed by three members, a gear box, a motor housing, and a rubber boot, in a cross section of the cable. The first connector provided on the cable sheath tube of the cable is fitted to the second connector provided on the motor housing,
When connecting the first terminal of the first connector and the second terminal of the second connector in the terminal connection space formed in the fitting portion of both connectors,
An air passage for the cable is provided in the tube of the electric wire cladding tube, an air passage in the first connector which is provided in the first connector and communicates the air passage in the electric wire cladding tube with the terminal connection space, and a second connector. 2. The electric power steering apparatus according to claim 1, further comprising a second connector air passage that communicates with the terminal connection space through a communication space between the gear box, the motor housing, and the rubber boot.

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