JP5767261B2 - Inspection apparatus for hollow assembly and inspection method for hollow assembly - Google Patents

Description

  The present invention relates to a technique for inspecting a hollow assembly represented by a differential case (hereinafter referred to as a differential case).

Generally, a differential device (a differential device) is disposed between the left and right drive wheels.
The differential device is a device that generates a difference in rotational speed between the left and right drive wheels to improve turning performance, and is a complex structure in which a plurality of gears are incorporated in a differential case.
Since differential devices are important components for vehicles, their performance is required to be above a certain level, and various inspection devices for differential devices have been proposed (for example, Patent Document 1 (No. 1). (See FIGS. 1 to 3).)

The structure of the differential device is shown in FIG.
In inspecting the differential shown in FIG. 1, measurement is carried out in two stages, FIG. 2 and FIG. Conventionally, only a single product was measured and not a differential device, but the invention of Patent Document 1 made it possible to measure the rotational resistance of the differential device.

By the way, it is assumed that the first stage inspection in FIG. 2 of Patent Document 1 passes, but the second stage inspection in FIG. 3 of Patent Document 1 fails.
If the second stage inspection fails, the bearing (4) (the numbers in parentheses indicate the reference numbers described in Patent Document 1. The same applies hereinafter), differential case (5), shaft (6), drive shaft (7, 8), I don't know where the gear (14) is.

In order to clarify the problem part, disassembly and re-examination are generally performed. However, if the bearing (4), differential case (5), shaft (6), drive shaft (7, 8), and gear (14) are individually inspected, the inspection will be repeated many times. Man-hours increase.
Therefore, a preferable inspection technique for the bearing (4), the differential case (5), the shaft (6), the drive shaft (7, 8), and the gear (14) is required.

Of the bearing (4), the differential case (5), the shaft (6), the drive shaft (7, 8), and the gear (14), the differential case (5) is a cast product, and the other bearings (4), The shaft (6), the drive shaft (7, 8), and the gear (14) are machined products.
Cast products are prone to uneven thickness and easily out of balance. On the other hand, machined products do not have to worry about uneven thickness and do not have to worry about being out of balance.

In general, cast products that are prone to uneven thickness are subjected to a balance machine to measure the unbalance amount.
However, since the balance machine is expensive, it is difficult to arrange it on the assembly line.
Therefore, an inspection technique capable of performing a rotation inspection without using a balance machine is required.

Japanese Patent Publication No. 2-55737

  An object of the present invention is to provide an inspection technique capable of performing a rotation inspection without using a balance machine.

  The inventors of the present invention can perform rotation inspection by attaching a machined bearing and gear to a cast product, rotatably supporting the cast product with the bearing, and measuring runout using the gear. As a result, the inventors have completed the invention described below.

The invention according to claim 1 includes a hollow cast product, a plurality of bearings attached to a shaft portion of the hollow cast product, and a product gear attached to the hollow cast product so that the center of the bearing is a rotation center. a hollow assembly inspected made, with as rotation axis is vertically provided with a supporting mechanism for supporting the hollow assembly through the bearing, in the inspection apparatus for inspecting the rotational characteristics of the hollow assembly, a support mechanism A rotating mechanism that rotates the supported hollow assembly at a predetermined speed, and the supporting mechanism includes at least an upper clamp member that sandwiches an upper bearing and a lower clamp member that sandwiches a lower bearing among a plurality of bearings, and these And a clamp member moving mechanism for horizontally moving the lower clamp member and the upper clamp member, and a detection piece extending vertically to at least one of the clamp members Provided, the second displacement gauge for measuring the horizontal displacement of the detecting piece to the clamp member moving mechanism is provided, characterized in that it comprises a determination unit for performing acceptability determination based on the displacement information obtained by the second displacement gauge And

The invention according to claim 2 is characterized in that an inspection gear meshed with the product gear and a first displacement meter for measuring the displacement of the gear shaft of the inspection gear are provided .

  In the invention according to claim 3, the hollow assembly as the inspection target is a hollow cast product, a pair of left and right first internal gears that can be fitted to a product drive shaft that is not the inspection target during the inspection, and the pair of first gears. A plurality of bearings that house a pair of second internal gears that mesh with the internal gears and that are attached to the shaft portion of the hollow cast product, and products that are attached to the hollow cast product with the center of these bearings being the center of rotation It is characterized by comprising a gear.

  In the invention according to claim 4, the product drive shaft that prevents one of the internal gears from rotating by being fitted to one of a pair of internal gears that can be fitted to a product drive shaft that is not an inspection target at the time of inspection. It is provided with a simulated lock shaft.

In the invention according to claim 5, the support mechanism moves the lower clamp member and the upper clamp member horizontally, the lower clamp member that holds the lower bearing among the bearings, the upper clamp member that holds the upper bearing, and the lower clamp member. A clamp member moving mechanism
The upper clamp member is provided with a detection piece extending upward, and the clamp member moving mechanism is provided with a second displacement meter for measuring the horizontal displacement of the detection piece.

In the invention according to claim 1, a hollow comprising a hollow cast product, a plurality of bearings attached to the shaft portion of the hollow cast product, and a product gear attached to the hollow cast product so that the center of the bearing is the center of rotation. In the inspection apparatus for inspecting the rotational characteristics of the hollow assembly, the assembly is provided with a support mechanism that supports the hollow assembly through a bearing so that the rotation axis is vertical, and is supported by the support mechanism. A rotation mechanism that rotates the hollow assembly at a predetermined speed, and the support mechanism includes at least an upper clamp member that sandwiches an upper bearing and a lower clamp member that sandwiches a lower bearing among a plurality of bearings, and these lower clamps A clamp member moving mechanism for horizontally moving the member and the upper clamp member, and at least one of the clamp members is provided with a detection piece extending vertically. The second displacement gauge is provided to measure the horizontal displacement of the detecting piece to the clamp member moving mechanism, and a determination unit for performing acceptability determination based on the displacement information obtained by the second displacement gauge.
A hollow assembly in which a machined bearing and a product gear are attached to a hollow cast product in which uneven thickness tends to occur is an inspection object.
In the present invention, the rotation axis is vertical. If the rotating shaft is leveled, the inner ring of the bearing inevitably falls due to the action of gravity. Although slightly, the center of the outer ring and the center of the inner ring are offset, which adversely affects the rotation inspection.
In this respect, in the present invention, since the rotation axis is vertical, no offset due to gravity action occurs, and rotation inspection can be performed under favorable conditions.
A detection piece is provided on the clamp member, and the detection piece is measured by a second displacement meter. The second displacement meter can detect runout caused by the bearing and the hollow casting.
In the present invention, a displacement meter is used for inspection. The displacement meter is a kind of non-contact type distance meter and is easily available and inexpensive. As a result, the cost of the inspection apparatus can be further reduced.
That is, according to the present invention, it is possible to perform a rotation inspection with an inexpensive inspection apparatus without using an expensive balance machine.

In the invention according to claim 2, the inspection gear meshed with the product gear and the first displacement meter for measuring the displacement of the gear shaft of the inspection gear are provided.
The product gear runout is measured with the first displacement meter. At that time, the hollow cast product is rotated by skillfully using the bearing included in the inspection object. As a result, the number of bearings provided in the inspection apparatus can be greatly reduced, and the cost of the inspection apparatus can be reduced.
The displacement of the gear shaft is measured in the first displacement form. The first displacement meter detects the vibration caused by the product gear and the hollow casting product, and the second displacement meter detects the vibration caused by the bearing and the hollow casting product .
A pass / fail decision is made based on information from both the first displacement meter and the second displacement meter. Since the determination material has increased, the reliability of the pass / fail determination is increased.

In the invention according to claim 3, the hollow assembly as the inspection target is a hollow cast product, a pair of left and right first internal gears that can be fitted to a product drive shaft that is not the inspection target during the inspection, and the pair of first gears. A pair of second internal gears that mesh with the internal gears are accommodated.
That is, in addition to the inspection of the hollow casting product, the first internal gear and the second internal gear can be inspected.

In the invention according to claim 4, the inspection device prevents one of the internal gears from rotating by being fitted to one of a pair of internal gears that can be fitted to a product drive shaft that is not a target for inspection. A lock shaft that mimics the product drive shaft is provided.
Since it is only necessary to add a lock shaft to the inspection apparatus, the inspection of the other inspection object can be performed without increasing the size and complexity of the apparatus.

In the invention according to claim 5, as in the case of claim 2, the acceptance / rejection determination is performed based on information of both the first displacement meter and the second displacement meter. Since the determination material has increased, the reliability of the pass / fail determination is increased.
In this invention, since the detection piece extends upward from the upper clamp member, the detection piece can be easily found to be bent or deformed, and the performance of the inspection apparatus can be maintained satisfactorily.

It is sectional drawing of a hollow assembly. It is a top view of the inspection apparatus for hollow assemblies concerning the present invention. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. FIG. 4 is a view taken along arrow 4 in FIG. 3. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a view taken along arrow 6 in FIG. 5. It is a figure which shows the modification of a hollow assembly. It is a figure which shows the modification of the inspection apparatus for hollow assemblies.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

As shown in FIG. 1, a hollow assembly 10 includes a hollow cast product 11 represented by a differential case, bearings 12 and 13 attached to both ends (lower and upper ends in the figure) of the hollow cast product 11, and these bearings. The product gear 14 is attached to the hollow casting 11 so that the center of the rotation centers 12 and 13 is the center of rotation. That is, the reference numeral 15 is a rotating shaft that is common to the hollow cast product 11, the bearings 12 and 13, and the product gear 14. The product gear 14 is a name for distinguishing from the inspection gear described later. In the case of differential, the ring gear corresponds to the product gear 14. Each of the bearings 12 and 13 includes an inner ring 16, an outer ring 17, and a rolling element 18.
An apparatus for inspecting the hollow assembly 10 having such a structure will be described below.

As shown in FIG. 2, a hollow assembly inspection device (hereinafter abbreviated as an inspection device) 20 includes a machine base 21, a rotation mechanism 30 disposed on the machine base 21, and the rotation mechanism 30. Thus, it comprises a support mechanism 40 disposed on the machine base 21, an inspection gear 51, and an inspection gear moving mechanism 50 that supports and moves the inspection gear 51.
The detailed structure of each mechanism 30, 40, 50 will be described below.

  As shown in FIG. 3, the support mechanism 40 is a mechanism that supports the hollow assembly 10 in the air via the upper and lower bearings 12 and 13, and a lower clamp that holds the lower bearing 12 out of the pair of bearings 12 and 13. Members 41L and 41R (L is a subscript indicating left and R is right; the same applies hereinafter), upper clamp members 43L and 43R that sandwich the upper bearing 13, and the lower clamp members 41L and 41R and the upper The clamp members 43L and 43R include clamp member moving mechanisms 44L and 44R that horizontally move the clamp members 43L and 43R.

  The left clamp member moving mechanism 44L is connected to a support base 45L fixed to the machine base 21, a cylinder unit 47 provided on the support base 45 and maintaining the piston rod 46 horizontally, and a tip of the piston rod 46. And a connecting member 48 for connecting the upper and lower clamp members 41L and 41R, and guide rods 49 and 49 that are slidably fitted to the support base 45 and guide the connecting member 48 so as not to swing up and down.

Since the right clamp member moving mechanism 44R is symmetrical with the left clamp member moving mechanism 44L, description of the configuration is omitted.
However, a detection piece 52 extending upward is provided on the right upper clamp member 43R, and a second displacement meter 53 for measuring the horizontal displacement of the detection piece 52 is provided on the clamp member moving mechanism 44R (specifically, the support base 45R). ing.

  The second displacement meter 53 is a kind of non-contact type distance meter, and includes a light projecting unit and a light receiving unit, and emits laser light or infrared light from the light projecting unit and receives reflected light from the light receiving unit. Is recommended. The light receiving unit includes a large number of light receiving elements, and geometrically measures the distance depending on where the light receiving elements are received. The difference between the reference distance and the measurement distance is the displacement. The second displacement meter 53 may be a millimeter wave radar. The same applies to a first displacement meter 62 described later.

As shown in FIG. 4, the clamp members 43L and 43R have a V-shaped portion at the tip. The V-shaped portion abuts on the outer ring 17 of the bearing 13 and exhibits a centering action as in the so-called V block. The outer ring 17 is clamped by the clamp members 43L and 43R while being centered.
When there is a problem with the bearing 13, for example, when the rolling element (ball or roller) 18 is scratched, the outer ring 17 swings when the inner ring 16 is turned. This shake is transmitted to the clamp member 43R, and the detection piece 52 is shaken. This shake is detected by the second displacement meter 53.

  As shown in FIG. 3, the detection piece 52 extends upward from the upper clamp member 43R. A second displacement meter 53 that detects the shake of the detection piece 52 is also placed on the support base 45R. With such a configuration, it is possible to easily check whether or not the detection piece 52 is bent and whether or not the second displacement meter 53, particularly the lens, is dirty.

Further, the detection piece 52 may extend downward from the lower clamp member 41R as indicated by an imaginary line, and the second displacement meter 53 may be incorporated in the support base 45R as indicated by an imaginary line.
Although inspection is difficult, there is an advantage that the detection piece 52 and the second displacement meter 53 are hardly damaged by an external force.

  As shown in FIG. 5, the rotation mechanism 30 includes a drive shaft 32 that is mounted vertically on the machine base 21 via a bearing 31, and a drive shaft 32 that is provided under the machine base 21 via a bracket 33 and that has a predetermined rotational speed. And a cylinder 35 attached to the machine base 21 so as to surround the upper portion of the drive shaft 32.

The cylindrical body 35 does not play a role of supporting the lower bearing 12, but has a role of holding the outer ring of the bearing 31 from above and a guide surface 36 that guides the lower end of the hollow casting 11 to the drive shaft 32. It plays a role of easily fitting the lower end of the hollow casting 11 to the shaft 32.
The motor 34 is preferably a servo motor, but may be a general-purpose motor with a built-in reduction gear.

  The inspection gear moving mechanism 50 includes a rail 54 laid on the machine base 21, a slider 55 that can be horizontally moved on the rail 54, an actuator 56 that horizontally moves the slider 55, and a horizontal movement to the slider 55. An L-shaped block 57 that can be freely mounted, a rod 58 that connects the L-shaped block 57 and the slider 55, a compression spring 59 that is disposed so as to surround the rod 58 and pushes out the L-shaped block 57 starting from the slider 55, Consists of.

Further, the gear shaft 61 is fixed to the L-shaped block 57 so as to vertically penetrate the L-shaped block 57, and the inspection gear 51 is rotatably supported on the upper portion of the gear shaft 61.
A first displacement meter 62 is housed in the slider 55, and the lower portion of the gear shaft 61 is monitored by the first displacement meter 62 to measure the shake of the gear shaft 61.

  As shown in FIG. 6, the slider 55 has a pair of guide parts 63, 63, and the L-shaped block 57 moves without shaking because the guide parts 63, 63 guide the L-shaped block 57. The inspection gear 51 meshes with the product gear 14 while being given a constant force by the compression spring 59, and the inspection gear 51 rotates with the product gear 14 in this state.

  In FIG. 5, when the hollow casting product 11 has uneven thickness, or when the product gear 14 is not correctly attached to the hollow casting product 11, the hollow casting product 11 and / or the product gear 14 are shaken, and this deflection is generated. This is transmitted to the inspection gear 51, and this transmission is transmitted to the gear shaft 61. The shake of the gear shaft 61 is detected by the first displacement meter 62.

The shake information of the first displacement meter 62 is transmitted to the determination unit 65. The determination unit 65 compares the allowable run-out with the measured run-out, and determines “pass” if the measured run is less than the allowable run, and determines “fail” if the measured run exceeds the allowable run-out. .
In addition, it is preferable to incorporate the information of the second displacement meter (FIG. 3, reference numeral 53) into the determination unit 65 and make a pass / fail determination based on the two types of information because the determination reliability increases.

Incidentally, a machine that measures an unbalance amount called a balance machine is a precision machine that can determine an offset amount between a correct center of gravity position and a measured center of gravity position, and is expensive because of its high performance.
In this regard, the inspection apparatus 20 according to the present invention is a simple structure as shown in FIGS. 2, 3, and 5, and the displacement meters 53 and 62 are also inexpensive, so the apparatus cost can be reduced. . That is, as shown in FIG. 3, when rotating the hollow casting product 11, the bearings 12 and 13 attached to the hollow casting product 11 are skillfully used.

The inspection is performed by the following procedure using the inspection apparatus 20 described above.
As shown in FIG. 3, the hollow assembly 10 is supported by the support mechanism 40 so that the rotating shaft 15 is vertical (support process).
As shown in FIG. 6, the inspection gear 51 is engaged with the product gear 14 (product gear setting step).

As shown in FIG. 3, the hollow assembly 10 is supported through bearings 12 and 13, and in FIG. 5, the hollow assembly 10 is rotated around the rotation shaft 15 at a constant rotational speed by the motor 34 and the drive shaft 32 (rotation). Process).
As shown in FIG. 5, the displacement (runout) of the gear shaft 61 of the inspection gear 51 meshing with the product gear 14 is measured by the first displacement meter 62 (first displacement measuring step).
Based on the displacement information obtained by the first displacement meter 62, a pass / fail determination is performed by the determination unit 65 (determination step).

The above inspection procedure is very simple, and the runout inspection of the hollow assembly in which the bearings 12 and 13 and the product gear 14 are attached to the hollow casting 11 is performed by this procedure.
Since the inspection method and the inspection device are simple, they can be arranged and operated on the assembly line.

The present invention can also be applied to a hollow assembly including internal gears (side gears and pinion gears). Specific examples will be described below.
A hollow assembly 10 shown in FIG. 7 includes a pair of left and right (upper and lower in this figure) first internal gears 72 and 72 that can be fitted to a hollow cast product 11 and a product drive shaft 71 that is not an inspection target during inspection. A pair of second internal gears 73, 73 meshing with the pair of first internal gears 72, 72 are accommodated, and the second internal gears 73, 73 are supported on the hollow casting 11 by the shaft member 74. In addition, providing the bearings 12 and 13 and the product gear 14 in the hollow casting 11 is the same as in FIG.
The first internal gear 72 is called a side gear in the differential, and the second internal gear 73 is called a pinion gear (or simply pinion) in the differential.

  The first and second internal gears 72 and 73 are forged products and may be machined after forging. Forged products and machined products may have dents during conveyance, and it is better if the presence or absence of dents in the first and second internal gears 72 and 73 can be confirmed.

An example of the inspection apparatus 20B for that purpose will be described below.
As shown in FIG. 8, in the inspection apparatus 20 </ b> B, a column 76 is erected on the machine base 21, and a lifting / lowering unit 77 such as a cylinder unit is attached to the tip of the column 76, and the lifting / lowering unit 77 is arranged downward on the vertical axis. A lock shaft 78 is attached. The lock shaft 78 imitates the tip of a product drive shaft called a drive shaft (FIG. 7, reference numeral 71) and is a non-rotating shaft. Since other configurations are the same as those in FIG. 5, reference numerals are used to omit the description.

When checking the presence or absence of dents on the first and second internal gears 72 and 73, the lock shaft 78 imitating the product drive shaft (drive shaft) that is not the object of inspection is lowered during the inspection, and the pair of first gears It is fitted to one of the internal gears 72 and 72 so as not to rotate.
Next, the inspection gear 51 meshed with the product gear 14 is rotated by giving a desired constant rotational speed to the hollow assembly 10 </ b> B as the inspection object in which the first and second internal gears 72 and 73 are accommodated. The displacement (runout) of the gear shaft 61 of the inspection gear 51 is measured by the first displacement meter 62 (corresponding to the first displacement measuring step).

When there is a problem with the first and second internal gears 72, 73, for example, when the first internal gear 72 is scratched, the first internal gear 72 vibrates when the hollow assembly 10B is turned. This vibration is transmitted to the clamp member 43R and causes the detection piece 52 to shake. This shake is detected by the second displacement meter 53. The presence or absence of dents in the first and second internal gears 72 and 73 can be confirmed.
At this time, needless to say, the inspection of the hollow casting 11 can be performed together.

  The hollow cast product is preferably a differential case, but may be a similar mechanical part. The product gear may be a helical gear, a bevel gear, or a so-called ring gear.

  The present invention is suitable for inspection of a differential case.

  DESCRIPTION OF SYMBOLS 10, 10B ... Hollow assembly, 11 ... Hollow casting product, 12, 13 ... Bearing, 14 ... Product gear, 15 ... Rotary shaft, 20, 20B ... Inspection apparatus for hollow assemblies, 21 ... Machine stand, 30 ... Rotation mechanism , 40 ... support mechanism, 41L, 41R ... lower clamp member, 43L, 43R ... upper clamp member, 44L, 44R ... clamp member moving mechanism, 50 ... inspection gear moving mechanism, 51 ... inspection gear, 52 ... detection piece, 53 ... 2nd displacement meter, 61 ... gear shaft, 62 ... 1st displacement meter, 65 ... determination part, 71 ... product drive shaft, 72 ... 1st internal gear, 73 ... 2nd internal gear, 78 ... lock shaft.

Claims (5)

A hollow assembly comprising a hollow cast product, a plurality of bearings attached to the shaft portion of the hollow cast product, and a product gear attached to the hollow cast product with the center of the bearing being the center of rotation. as provided with a supporting mechanism for supporting the hollow assembly as rotation axis is vertically through the bearing, in the inspection apparatus for inspecting the rotational characteristics of the hollow assembly is supported by the support mechanism wherein A rotation mechanism for rotating the hollow assembly at a predetermined speed ,
The support mechanism includes at least an upper clamp member that holds an upper bearing and a lower clamp member that holds a lower bearing among the plurality of bearings, and a clamp member movement that horizontally moves the lower clamp member and the upper clamp member. The mechanism,
At least one of the clamp members is provided with a detection piece extending vertically, and the clamp member moving mechanism is provided with a second displacement meter for measuring a horizontal displacement of the detection piece,
A determination unit that performs a pass / fail determination based on the displacement information obtained by the second displacement meter;
An inspection apparatus for a hollow assembly characterized by the above. An inspection gear meshed with the product gear;
2. The inspection device for a hollow assembly according to claim 1, further comprising a first displacement meter for measuring the displacement of the gear shaft of the inspection gear. The hollow assembly as the inspection object is:
The hollow cast product accommodates a pair of left and right first internal gears that can be fitted to a product drive shaft that is not the object of inspection at the time of inspection, and a pair of second internal gears that mesh with the pair of first internal gears. A plurality of the bearings attached to the shaft portion of the hollow casting product, and the product gear attached to the hollow casting product such that the center of these bearings is the center of rotation. The inspection device for a hollow assembly according to claim 1 or 2.   A lock shaft imitating the product drive shaft that prevents one of the internal gears from rotating by being fitted to one of a pair of internal gears that can be fitted to the product drive shaft that is not an inspection target during the inspection. The inspection apparatus for a hollow assembly according to claim 3, further comprising: The support mechanism includes a lower clamp member that holds a lower bearing among the bearings, an upper clamp member that holds an upper bearing, and a clamp member moving mechanism that horizontally moves the lower clamp member and the upper clamp member. Consists of
The hollow assembly according to claim 1 , wherein a detection piece extending upward is provided on the upper clamp member, and a second displacement meter for measuring a horizontal displacement of the detection piece is provided on the clamp member moving mechanism. Three-dimensional inspection device.

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