JP7475607B2 - Sensor fixing structure and method - Google Patents

Description

The present invention relates to a sensor fixing structure and method, and in particular to a new improvement for connecting a sensor case to a motor case by crimping a part of a cylinder provided on the motor case into an annular groove in the sensor case when fixing the motor case to the sensor case.

As a conventional structure and method for fixing a sensor case to a motor case, for example, the structure shown in FIG. 9 of Japanese Patent Laid-Open No. 2003-233666 can be given.
In FIG. 9, reference numeral 10 denotes a servomotor consisting of a wound-type resolver 20 and a motor 5 . The resolver 20 includes a rotary transformer 11 to constitute a sensor 25 .

A motor shaft 7 is rotatably provided via bearings 6 within a motor case 30 that constitutes the motor 5 , and the motor shaft 7 is connected to a resolver rotor 21 of the resolver 20 .
A plurality of first screws 23 provided on the sensor case 22 of the resolver 20 are screwed into the motor case 30 , so that the sensor case 22 and the motor case 30 form an integrated servo motor 10 .

JP 2019-27933 A

Conventional sensor and motor connection structures used screws, so the sensor attached to the rear end of the motor was actually fixed in place using mounting claws and screws. The same number of mounting claws were required as screws, and tightening the screws took time.
In addition, tightening the screws requires space for the female screw tap and a seating surface, which requires more space than the sensor.

The present invention has been made to solve the above problems, and in particular to provide a configuration and method for fastening a motor case of a motor to a sensor case of a sensor by crimping a part of a cylinder provided on the motor case into an annular groove of the sensor case to connect the sensor case to the motor case.

The sensor fixing structure according to the present invention comprises a disk-shaped motor case having a cylinder integrally formed on one side thereof with a predetermined thickness, the cylinder having a diameter smaller than the outer diameter , a disk-shaped sensor inserted or fitted inside the cylinder, an annular groove formed on the outer periphery of an end of the sensor, and a crimping wall formed in a part of the cylinder and thinner than a base thereof, the crimping wall corresponding to the annular groove, and the motor case and the sensor are crimped together by bending the crimping wall into the annular groove, the crimping wall having any one of a shape formed entirely of a cylinder, a shape formed with a plurality of independent protrusions, and a shape formed with a plurality of slits, the tip of the crimping wall after bending is configured to abut against a corner of the annular groove, the motor case and the sensor are configured to be disk-shaped, In addition, a sensor fixing method according to the present invention uses a disk-shaped motor case having a cylindrical body of a predetermined thickness integrally formed on one side, the diameter of the cylindrical body being smaller than the outer diameter, a disk-shaped sensor inserted or fitted inside the cylindrical body, an annular groove formed on the outer periphery of an end of the sensor, and a crimping wall formed in a part of the cylindrical body and thinner than its base, the crimping wall corresponding to the annular groove, and the crimping wall is bent into the annular groove to crimp the motor case and the sensor, the crimping wall having any one of a shape formed entirely of a cylinder, a shape formed with a plurality of independent protrusions, and a shape formed with a plurality of slits, the tip of the crimping wall after bending abuts against a corner of the annular groove, and the motor case and the sensor are disk-shaped.

Since the sensor fixing structure and method according to the present invention are configured as described above, the following effects can be obtained.
That is, the servo motor comprises a motor case having a cylindrical body of a predetermined thickness integrally formed on one side, a sensor inserted or fitted inside the cylindrical body, an annular groove formed on the outer periphery of the end of the sensor, and a crimping wall formed in a part of the cylindrical body and thinner than its base, the crimping wall corresponding to the annular groove, and the motor case and the sensor are crimped together by bending the crimping wall into the annular groove. Therefore, by crimping the crimping wall into the annular groove, the motor case and the sensor can be easily and firmly joined, thereby improving the mass productivity of servo motors.
In addition, by using a shape of the tightening wall that is entirely cylindrical, has a plurality of independent protrusions, or has a plurality of slits, the tightening wall can be easily bent, making the tightening operation easier.
Furthermore, since the tip end of the bent crimping wall abuts against the corner of the annular groove, the bent crimping wall is reliably fixed, improving the reliability of crimping.
Since the motor case and the sensor are disk-shaped, the flat sensor and the motor can be easily and firmly coupled.

1 is a perspective view showing a motor case in a sensor fixing structure and method according to an embodiment of the present invention; FIG. 2 is a perspective view showing a motor case and a sensor shown in FIG. 1 . FIG. 3 is a perspective view of the motor case and the sensor in FIG. 2 in a crimped state. FIG. 4 is a cross-sectional view of FIG. 5 is an enlarged cross-sectional view of a main part showing a state before part A in FIG. 4 is crimped. FIG. FIG. 6 is an enlarged cross-sectional view of the main part of FIG. 5 after crimping. FIG. 2 is an enlarged perspective view showing another embodiment in which a protruding piece is used for the caulking wall of FIG. 1 . FIG. 8 is an enlarged perspective view showing another embodiment in which slits are used in the crimping wall of FIG. 7 . FIG. 11 is a cross-sectional view showing a conventional configuration.

The sensor fixing structure and method according to the present invention, when fixing the motor case of the motor and the sensor case of the sensor, connects the sensor case to the motor case by crimping a part of a cylinder provided on the motor case into an annular groove of the sensor case.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a sensor fixing structure and method according to the present invention will be described with reference to the drawings.
In addition, parts that are the same as or equivalent to those in the conventional configuration are denoted by the same reference numerals.
In FIG. 1, the reference numeral 30 denotes a disk-shaped motor case. At the center of this motor case 30, a cylindrical body 32 is formed which rises integrally from one surface 31 of the motor case 30 and has a predetermined thickness (first thickness W1).

A through hole 33 is formed in the center of the cylindrical body 32, and an annular groove 24 is formed on the outer periphery 25a of the end of the sensor 25, as clearly shown in Figures 5 and 6.

As shown in FIG. 5, the cylindrical body 32 is configured with a base 35 having a thickness (first thickness W1) of a predetermined thickness along the radial direction of the motor case 30, and a crimping wall 36 having a thickness (second thickness W2) thinner than the base 35. In other words, the relationship W1>W2 is set.

As shown in FIGS. 3 to 6 , the sensor 25 is provided inside the cylindrical body 32 by insertion or fitting, and the crimping wall 36 corresponds to the annular groove 24 .
The crimping wall 36 is bent and crimped into the annular groove 24 by a jig not shown (as shown in Figures 5 to 6), so that the motor case 30 and the sensor 25 are firmly crimped and inseparably joined to each other.
As shown in FIG. 6, a tip end 36a of the crimping wall 36 abuts against an inner corner 24c of the annular groove 24 after crimping.
This ensures that the sensor 25 and the motor case 30 are firmly connected to each other.

The tightening wall 36 may have any one of the following shapes: an overall cylindrical body 32A like the tube body 32 disclosed in Figures 1 to 6 above; a shape in which a plurality of independent protrusions 36A are formed as shown in Figure 7; and a shape in which a plurality of slits 36B are formed as shown in Figure 8.
As shown in Figures 1 and 2, in the case of a cylindrical tightening wall 36 that does not have the aforementioned protrusions 36A and slits 36B, a strong tightening jig is required, but in the case of a tightening wall 36 in which the protrusions 36A or slits 36B are formed, tightening is possible with a jig with a weaker tightening force than that described above.

The sensor fixing structure and method according to the present invention forms a thin crimping wall on a part of the cylinder that rises from the motor case, and by bending this crimping wall into an annular groove formed on the outer periphery of the sensor, the motor case and the sensor can be joined together as a single unit, allowing for the assembly of a servo motor with a simple structure.

24 Annular groove 24c Corner 25 Sensor 25a End outer circumference 30 Motor case 31 One surface 32 Cylindrical body 32A Cylindrical body 33 Through hole 35 Base 36 Crimping wall 36A Projecting piece (crimping wall)
36B Slit 36a Tip W1 First thickness (wall thickness)
W2 Second thickness (thin)

Claims (6)

a motor case (30) having a disk shape, a cylindrical body (32) having a predetermined thickness (first thickness W1) integrally formed on one surface (31), the diameter of the cylindrical body (32) being smaller than the outer diameter ;
A disk-shaped sensor (25) inserted or fitted inside the cylindrical body (32) ;
An annular groove (24) formed on the outer periphery (25a) of the end of the sensor (25) ;
a crimping wall (36) formed in a part of the cylindrical body (32) and having a thickness (second thickness W2) thinner than a base portion (35) of the cylindrical body (32) ;
It consists of :
The crimping wall (36) corresponds to the annular groove (24), and the motor case (30) and the sensor (25) are crimped together by bending the crimping wall (36) into the annular groove (24). The sensor fixing structure according to claim 1, characterized in that the crimping wall (36) is either an overall cylindrical body (32A), a shape with multiple independent protrusions (36A), or a shape with multiple slits (36B). The sensor fixing structure according to claim 1 or 2, characterized in that the tip portion (36a) of the crimping wall (36) after bending abuts against the corner portion (24c) of the annular groove (24). a motor case (30) having a disk shape, a cylindrical body (32) having a predetermined thickness (first thickness W1) integrally formed on one surface (31), the diameter of the cylindrical body (32) being smaller than the outer diameter ;
A disk-shaped sensor (25) inserted or fitted inside the cylindrical body (32) ;
An annular groove (24) formed on the outer periphery (25a) of the end of the sensor (25) ;
a crimping wall (36) formed in a part of the cylindrical body (32) and having a thickness (second thickness W2) thinner than a base portion (35) of the cylindrical body (32) ;
Using ​
The sensor fixing method is characterized in that the crimping wall (36) corresponds to the annular groove (24), and the motor case (30) and the sensor (25) are crimped and connected by bending the crimping wall (36) into the annular groove (24). The sensor fixing method according to claim 4, characterized in that the crimping wall (36) has any one of the following shapes: an entire cylindrical body (32A), a shape having a plurality of independent protrusions (36A), and a shape having a plurality of slits ( 36B ). 6. The sensor fixing method according to claim 4 , wherein a tip portion (36a) of the crimping wall (36) after bending is in contact with a corner portion (24c) of the annular groove (24).

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