JP2023145913A - Caulking device for gas sensor - Google Patents

Abstract

To reduce variations in a caulking load.SOLUTION: In a caulking device 10, a hole 50 for storing a gas sensor 12 and a plurality of caulking jigs 38 is formed in a pressing jig 34. An inner wall surface 52 of the pressing jig 34 forming the hole 50 includes a plurality of first inclined planes 60 that are inclined relative to a center axis 42 of the gas sensor 12 in order to press each of the plurality of caulking jigs 38 against the gas sensor 12. Each of the plurality of caulking jigs 38 includes a second inclined plane 78 that is brought into surface-contact with the corresponding first inclined plane 60 in the plurality of first inclined planes 60.SELECTED DRAWING: Figure 1

Description

The present invention relates to a caulking device for a gas sensor.

Patent Document 1 discloses a caulking device for a gas sensor. The crimping device crimps the gas sensor radially inward of the gas sensor. Specifically, the crimping device includes a pressing jig and a plurality of crimping jigs. A hole is formed in the pressing jig to accommodate a gas sensor and a plurality of crimping jigs. The inner wall surface of the pressing jig that forms the hole is tapered (conical) with respect to the axis of the gas sensor.

This crimping device crimps the gas sensor using the method described below. First, a plurality of crimping jigs are arranged around the axis of the gas sensor. Next, by moving the pressing jig relatively along the axial direction of the gas sensor, the gas sensor is inserted into the pressing jig, and the inner wall surface of the pressing jig is brought into contact with the back surface of the multiple crimping jigs. let Next, by further moving the pressing jig along the axial direction of the gas sensor, the plurality of crimping jigs are pressed against the gas sensor. Thereby, the gas sensor is crimped radially inward of the gas sensor.

Patent No. 5810120

As described above, the inner wall surface of the pressing jig is inclined in a tapered shape (conical shape) with respect to the axis of the gas sensor. Therefore, the radius of curvature of the inner wall surface of the pressing jig changes along the axial direction of the gas sensor. Specifically, the radius of curvature of the inner wall surface increases as it approaches the gas sensor and the crimping jig. Therefore, among the inner wall surfaces of the pressing jig, the radius of curvature of the open end (the inlet portion into which the gas sensor is inserted) close to the gas sensor and the crimping jig is the largest.

On the other hand, the back surface of each of the plurality of crimping jigs is a contact surface with the inner wall surface of the pressing jig, and is formed in a tapered shape corresponding to the inner wall surface of the pressing jig. The back surface of the crimping jig has a radius of curvature that is approximately the same as the radius of curvature of the opening end.

Therefore, when crimping the gas sensor, the more the pressing jig moves toward the gas sensor, the smaller the contact area between the crimping jig and the inner wall surface of the pressing jig becomes. As a result, if the contact positions between each of the plurality of crimping jigs and the pressing jig along the axial direction of the gas sensor differ from each other, the crimping load will vary. Furthermore, due to manufacturing variations in the plurality of crimping jigs, the crimping load varies even if the contact positions between the plurality of crimping jigs and the pressing jig differ along the axial direction of the gas sensor.

The present invention aims to solve the above-mentioned problems.

An aspect of the present invention includes a plurality of crimping jigs arranged around an axis of a gas sensor extending along an axial direction and for crimping the gas sensor, and a plurality of crimping jigs that move along the axial direction to A gas sensor crimping device comprising: a pressing jig for pressing a tightening jig against the gas sensor; The inner wall surface of the pressing jig that forms the hole has a plurality of first inclined planes that are inclined with respect to the axis of the gas sensor in order to press each of the plurality of crimping jigs against the gas sensor, Each of the plurality of caulking jigs has a second inclined plane that is in surface contact with a corresponding first inclined plane among the plurality of first inclined planes.

In the present invention, the second inclined plane of each of the plurality of crimping jigs makes surface contact with the corresponding first inclined plane. Thereby, when the crimping jig slides along the first inclined plane, the first inclined plane and the second inclined plane come into smooth surface contact over the entire surface of the first inclined plane. As a result, variations in caulking load can be reduced.

FIG. 1 is a sectional view of the crimping device. FIG. 2 is a plan view of a pressing jig and a plurality of crimping jigs. FIG. 3 is an enlarged plan view of the crimping jig. FIG. 4 is a rear view of the crimping jig. FIG. 5 is a sectional view showing the operation of the crimping device. FIG. 6 is a sectional view showing the operation of the crimping device. FIG. 7 is a sectional view showing the operation of the crimping device. FIG. 8 is a sectional view showing the operation of the crimping device.

FIG. 1 is a sectional view of a gas sensor crimping device 10 according to the present embodiment. In the following description, the "gas sensor crimping device 10" will be referred to as the "crimping device 10."

The gas sensor 12 is, for example, a gas sensor that measures the gas concentration of a specific gas among the gases to be measured. The gas sensor 12 includes a cylindrical body 14, a sensor element (not shown), a connector (not shown), a grommet 16, and a lead wire 18.

The cylindrical body 14 extends in a predetermined direction. In FIG. 1, the cylindrical body 14 extends in the vertical direction. The axial direction of the cylindrical body 14 is the axial direction of the gas sensor 12. A screw nut 20 is attached to the outer peripheral surface of the cylindrical body 14. The sensor element and the connector are arranged inside the cylindrical body 14. The connector is connected to the sensor element. Grommet 16 is an elastic body such as rubber. Grommet 16 is attached to base end 22 of cylindrical body 14 . Lead wire 18 is connected to the connector. The lead wire 18 is inserted through a through hole (not shown) formed in the grommet 16 and drawn out to the outside.

The base end portion 22 of the cylindrical body 14 and the grommet 16 are crimped radially inward of the cylindrical body 14 by the crimping device 10 . The caulked base end portion 22 and grommet 16 constitute a caulking portion 24 . The caulking portion 24 is formed in an uneven shape when viewed from the side. By forming the caulking portion 24, the inside of the cylindrical body 14 is sealed. In addition, in the gas sensor 12, the location where the caulking portion 24 is formed is the base end portion of the gas sensor 12. Further, in the gas sensor 12, a portion on the opposite side from the base end portion (the crimped portion 24) becomes a distal end portion of the gas sensor 12.

The crimping device 10 includes a driving source (not shown), a connecting plate 26, a base plate 28, a plurality of connecting rods 30, a first guide 32, a pressing jig 34, a second guide 36, and a plurality of connecting rods 30. A caulking jig 38 and a plurality of spring members 40 are provided. The crimping device 10 is provided so that, when crimping the gas sensor 12, the central axis 42 (axis, axis) of the gas sensor 12 and the central axis 44 of the crimping device 10 are substantially coaxial.

The driving source is, for example, a cylinder. The rod of the cylinder extends substantially coaxially with the central axis 44 (central axis 42). The rod of the cylinder is connected to a connecting plate 26. The connecting plate 26 is a plate-like member that is perpendicular to the central axis 44 . The connecting plate 26 is arranged substantially coaxially with the central axis 44 .

Base plate 28 is arranged between connection plate 26 and gas sensor 12. The base plate 28 is a plate-like member that is perpendicular to the central axis 44 . The base plate 28 is arranged substantially coaxially with the central axis 44.

Each of the plurality of connecting rods 30 is connected to opposing planes of the connecting plate 26 facing the base plate 28. Each of the plurality of connecting rods 30 is connected to an outer peripheral portion of the plane of the connecting plate 26. Each of the plurality of connecting rods 30 extends from the connecting plate 26 along the central axis 44 . The plurality of connecting rods 30 are inserted through the plurality of through holes 46 formed in the base plate 28.

The first guide 32 is a cylindrical member. A through hole 48 of a size into which the gas sensor 12 can be inserted is formed inside the first guide 32 . The first guide 32 is arranged on a plane of the base plate 28 that faces the gas sensor 12 . The first guide 32 is arranged on the base plate 28 substantially coaxially with the central axis 44 .

The pressing jig 34 is a tapered (conical) jig. A hole 50 having a size that can accommodate the gas sensor 12 and the plurality of crimping jigs 38 is formed inside the pressing jig 34 . The pressing jig 34 is arranged approximately coaxially with the central axis 44 by fitting the hole 50 with the outer peripheral surface of the first guide 32 . That is, the hole 50 is located approximately coaxially with the central axis 44. A plurality of connecting rods 30 are connected to the pressing jig 34.

The pressing jig 34 is slidable along the outer peripheral surface of the first guide 32. Specifically, the inner wall surface 52 of the pressing jig 34 that forms the hole 50 has a tapered surface 54 and a straight surface 56.

The straight surface 56 is formed in a portion of the inner wall surface 52 that is close to the base plate 28 . Straight surface 56 extends along central axis 44 . The radius of curvature (inner diameter) of the straight surface 56 is a substantially constant radius of curvature along the central axis 44 . The straight surface 56 is in contact with the outer peripheral surface of the first guide 32. That is, the inner diameter of the straight surface 56 is approximately the same as the outer diameter of the first guide 32.

The tapered surface 54 is formed in a portion of the inner wall surface 52 that is close to the gas sensor 12 . Tapered surface 54 is connected to straight surface 56. The radius of curvature of the tapered surface 54 changes along the central axis 44. Specifically, the radius of curvature of the tapered surface 54 increases as it approaches the gas sensor 12 from the straight surface 56 along the central axis 44. Therefore, the radius of curvature of the tapered surface 54 at the open end 58 of the pressing jig 34 that is close to the gas sensor 12 is the largest.

A plurality of first inclined planes 60 that are inclined with respect to the central axis 44 are formed on the tapered surface 54 (see FIGS. 1 and 2). The plurality of first inclined planes 60 are formed in the tapered surface 54 in the same number as the plurality of crimping jigs 38. The plurality of first inclined planes 60 are formed on the tapered surface 54 at predetermined angular intervals (equal intervals) around the central axis 44. Each of the plurality of first inclined planes 60 is formed from the open end 58 of the pressing jig 34 to the straight surface 56.

The second guide 36 is a cylindrical member. A through hole 62 is formed inside the second guide 36 and is large enough to allow the gas sensor 12 to pass therethrough. The second guide 36 is fixed to the first guide 32 by a plurality of screw members 64. The second guide 36 is arranged substantially coaxially with the central axis 44 . A plurality of guide holes 66 communicating with the through holes 62 are formed in the second guide 36 . The plurality of guide holes 66 are formed in the second guide 36 in a direction perpendicular to the central axis 44 (radial direction). The plurality of guide holes 66 are formed around the central axis 44 at predetermined angular intervals (equal intervals). A recess 68 is formed on the outer peripheral surface of the second guide 36 above the guide hole 66 .

The plurality of caulking jigs 38 are arranged to be housed between the tapered surface 54 and the second guide 36 inside the pressing jig 34 . The plurality of crimping jigs 38 are arranged at predetermined angular intervals (equal intervals) around the central axis 44 (see FIG. 2). That is, each of the plurality of crimping jigs 38 is arranged between the corresponding first inclined plane 60 and the second guide 36 among the plurality of first inclined planes 60.

Specifically, each of the plurality of caulking jigs 38 has a base end portion 70, an extension portion 72, and two claw portions 74 and 76. The proximal end portion 70 has a second inclined plane 78 in surface contact with the first inclined plane 60 . A grease reservoir 80 is provided on the second inclined plane 78 . Grease (not shown) is supplied to the grease reservoir 80. The extending portion 72 extends from the base end portion 70 toward the central axis 44 . The extending portion 72 is inserted into a corresponding one of the plurality of guide holes 66 .

Two claw parts 74 and 76 are formed at the tip of the extension part 72. The two claw portions 74 and 76 are provided at the tip of the extension portion 72 along the central axis 44 at a predetermined interval. One claw portion 76 is closer to the gas sensor 12 along the central axis 44 than the other claw portion 74 . Note that it is desirable that one claw portion 76 protrudes slightly more toward the central axis 44 than the other claw portion 74 .

Each of the plurality of spring members 40 is connected to the base end portion 70 of the corresponding crimping jig 38 among the plurality of crimping jigs 38 and the corresponding recess 68 among the plurality of recesses 68 of the second guide 36. inserted between. Each of the plurality of spring members 40 biases the corresponding crimping jig 38 so that the corresponding crimping jig 38 separates from the central axis 44 .

2 to 4 illustrate the configuration of a plurality of crimping jigs 38. As shown in FIG. 2, the crimping device 10 (see FIG. 1) includes eight crimping jigs 38. The pressing jig 34 has eight first inclined planes 60. The eight first inclined planes 60 are formed around the central axis 44 at intervals of 45°. Therefore, the eight crimping jigs 38 are arranged at 45° intervals around the central axis 44.

Note that the number of crimping jigs 38 shown in FIG. 2 is an example. In the crimping device 10, two or more crimping jigs 38 may be arranged at equal intervals around the central axis 44. For example, four or five crimping jigs 38 may be arranged at equal intervals around the central axis 44.

As shown in FIG. 3, the two claw portions 74 and 76 of the caulking jig 38 are formed in an arc shape in plan view. This allows each of the two claw parts 74 and 76 to come into surface contact with the cylindrical body 14 (see FIG. 1) of the gas sensor 12.

As shown in FIG. 4, the grease reservoir 80 is a rectangular slit provided in the second inclined plane 78. As shown in FIG.

Next, a method for crimping the gas sensor 12 using the crimping device 10 will be described with reference to FIG. 1 and FIGS. 5 to 8.

First, as shown in FIG. 5, the gas sensor 12 is placed above the caulking device 10. In this case, the tip of the gas sensor 12 faces the through hole 62 of the second guide 36 so that the central axis 42 of the gas sensor 12 and the central axis 44 of the crimping device 10 are substantially coaxial.

Next, as shown in FIG. 6, the gas sensor 12 is inserted inside the first guide 32 in the direction of arrow A along the central axis 42 (central axis 44). In this case, the gas sensor 12 is inserted inside the first guide 32 so that the base end 22 of the cylindrical body 14 and the two claws 74 and 76 of each of the plurality of crimping jigs 38 face each other. Note that the crimping device 10 uses a retracting mechanism (not shown) to grasp the screw nut 20 of the gas sensor 12 and pull the gas sensor 12 to a predetermined position inside the first guide 32, thereby moving the gas sensor 12 into the first position. It is also possible to insert it inside the guide 32.

Next, as shown in FIG. 7, the drive source is driven to move (raise) the connecting plate 26 in the direction of arrow B toward the gas sensor 12. As mentioned above, the pressing jig 34 is connected to the connection plate 26 via the plurality of connection rods 30. Therefore, the pressing jig 34 slides (rises) in the direction of arrow B along the outer peripheral surface of the first guide 32 as the connection plate 26 rises.

The second inclined plane 78 of each of the plurality of caulking jigs 38 is in surface contact with the first inclined plane 60 of the pressing jig 34. As the pressing jig 34 rises, the base end portion 70 of each of the plurality of crimping jigs 38 slides on the corresponding first inclined plane 60. Specifically, the base end portion 70 slides on the first inclined plane 60 so as to descend toward the straight surface 56 as the pressing jig 34 rises. As a result, the extending portion 72 connected to the base end portion 70 moves in the direction of arrow C toward the base end portion 22 of the cylindrical body 14 against the biasing force of the spring member 40.

When the pressing jig 34 further rises, the two claws 74 and 76 of each of the plurality of crimping jigs 38 come into contact with the base end 22 of the cylindrical body 14. The two claws 74 and 76 press the base end 22 of the cylindrical body 14 and the grommet 16 inward in the radial direction of the cylindrical body 14 . As a result, the base end portion 22 of the cylindrical body 14 and the grommet 16 are crimped, and a crimped portion 24 is formed. As a result, the inside of the gas sensor 12 becomes airtight. Note that when the claw portion 76 protrudes further toward the central axis 44 than the claw portion 74, the portion of the caulking portion 24 that is pressed by the claw portion 76 is smaller than the portion that is pressed by the claw portion 74. It is crimped to the inside of the cylindrical body 14 in the radial direction.

After the crimped portion 24 is formed, as shown in FIG. 8, the driving source is driven to lower the connecting plate 26 in the direction of arrow D. Since the pressing jig 34 is connected to the connection plate 26 via the plurality of connection rods 30, it slides (descends) along the outer peripheral surface of the first guide 32 in the direction of arrow D.

As the pressing jig 34 descends, the base end portion 70 of each of the plurality of crimping jigs 38 slides along the first inclined plane 60. Specifically, the base end portion 70 slides on the first inclined plane 60 so as to approach the open end 58 as the pressing jig 34 descends. In this case, a biasing force is applied to the base end portion 70 by the spring member 40 to move it away from the central axis 44 . Therefore, the extending portion 72 connected to the base end portion 70 is separated from the cylindrical body 14 in the direction of arrow E due to the sliding movement of the base end portion 70 and the biasing force of the spring member 40. Thereby, the caulking part 24 of the gas sensor 12 is released from the pressed state by the two claw parts 74 and 76.

When the pressing jig 34 further descends, the base end portion 70 of each of the plurality of crimping jigs 38 slides to the vicinity of the open end 58 of the first inclined plane 60. As a result, the two claw portions 74 and 76 retreat to the guide hole 66.

Next, as shown in FIG. 1, the gas sensor 12 is raised in the direction of arrow F, and the gas sensor 12 is taken out from the crimping device 10.

Note that the present invention is not limited to the embodiments described above, and can take various configurations without departing from the gist of the present invention.

The invention that can be understood from the above embodiments will be described below.

An aspect of the present invention includes a plurality of crimping jigs (38) arranged around the axis of the gas sensor (12) extending along the axial direction and for crimping the gas sensor, and a plurality of crimping jigs (38) that move along the axial direction. A gas sensor crimping device (10) comprising a pressing jig (34) for pressing a plurality of crimping jigs against the gas sensor, the pressing jig including the gas sensor and the plurality of crimping jigs. A hole (50) for accommodating a tightening jig is formed, and an inner wall surface (52) of the pressing jig forming the hole is configured to press each of the plurality of tightening jigs against the gas sensor. It has a plurality of first inclined planes (60) that are inclined with respect to the axis (42) of the gas sensor, and each of the plurality of caulking jigs has a corresponding first inclined plane among the plurality of first inclined planes. It has a second inclined plane (78) that makes surface contact with the plane.

In the present invention, the second inclined plane of each of the plurality of crimping jigs makes surface contact with the corresponding first inclined plane. Thereby, when the crimping jig slides along the first inclined plane, the first inclined plane and the second inclined plane come into smooth surface contact over the entire surface of the first inclined plane. As a result, variations in caulking load can be reduced.

In an aspect of the present invention, the plurality of first inclined planes are inclined planes that approach the gas sensor as they advance inside the pressing jig.

Thereby, it is possible to further suppress variations in the crimping load, and it is also possible to crimp the gas sensor with high accuracy.

In an aspect of the present invention, a grease reservoir (80) is provided on the second inclined plane of each of the plurality of crimping jigs.

Thereby, it becomes possible to suitably supply grease from the grease reservoir to the first inclined plane and the second inclined plane, so that the sliding movement between the first inclined plane and the second inclined plane becomes good. As a result, it is possible to reduce variations in the crimping load caused by wear of the pressing jig and the crimping jig and sliding loads on the first inclined plane and the second inclined plane.

In an aspect of the present invention, the plurality of first inclined planes are arranged at equal intervals around the axis of the gas sensor, and each of the plurality of crimping jigs is arranged on the first inclined plane to which the second inclined plane corresponds. They are arranged at equal intervals around the axis of the gas sensor so as to be in surface contact with the gas sensor.

This makes it possible to make the contact position of the crimping jigs with respect to the gas sensor and the contact friction force of the crimping jigs with respect to the gas sensor approximately equal among the plurality of crimping jigs. As a result, variations in crimping load can be further reduced.

In an aspect of the present invention, the crimping device further includes a plurality of spring members (40) that bias the plurality of crimping jigs so that the crimping jigs are spaced apart from the gas sensor.

Thereby, after the gas sensor is crimped, the crimping jig can be quickly separated from the gas sensor.

10...Crimp device (gas sensor caulk device)
12... Gas sensor 34... Pressing jig 38... Crimping jig 42... Central axis (axis line)
50... Hole 52... Inner wall surface 60... First inclined plane 78... Second inclined plane

Claims (5)

A plurality of crimping jigs are arranged around an axis of a gas sensor extending along an axial direction to swage the gas sensor, and a plurality of crimping jigs are moved along the axial direction to tighten the crimping jigs to the gas sensor. A gas sensor crimping device comprising a pressing jig for pressing the gas sensor,
A hole is formed in the pressing jig to accommodate the gas sensor and the plurality of crimping jigs,
The inner wall surface of the pressing jig that forms the hole has a plurality of first inclined planes that are inclined with respect to the axis of the gas sensor in order to press each of the plurality of caulking jigs against the gas sensor. ,
Each of the plurality of crimping jigs is a crimping device for a gas sensor, wherein each of the plurality of crimping jigs has a second inclined plane that makes surface contact with a corresponding first inclined plane among the plurality of first inclined planes. The gas sensor crimping device according to claim 1,
In the gas sensor crimping device, the plurality of first inclined planes are inclined planes that get closer to the gas sensor as they advance into the pressing jig. The gas sensor crimping device according to claim 1 or 2,
A crimping device for a gas sensor, wherein a grease reservoir is provided on the second inclined plane of each of the plurality of crimping jigs. The gas sensor crimping device according to any one of claims 1 to 3,
The plurality of first inclined planes are arranged at equal intervals around the axis of the gas sensor,
A crimping device for a gas sensor, wherein each of the plurality of crimping jigs is arranged at equal intervals around an axis of the gas sensor so that the second inclined plane is in surface contact with the corresponding first inclined plane. The gas sensor crimping device according to any one of claims 1 to 4,
A crimping device for a gas sensor, further comprising a plurality of spring members that bias the plurality of crimping jigs so that the plurality of crimping jigs are spaced apart from the gas sensor.

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