JPH04256818A - Method and apparatus for inspecting sealing property of sealing element - Google Patents

Abstract

PURPOSE:To inspect the presence or absence of a defect in sealing property highly accurately even if there is dispersion in the inner diameter of the lip part of a ring-shaped sealing element as an object of inspection. CONSTITUTION:A shaft 23 is inserted into a shaft inserting hole 20 of a ring- shaped sealing element 19. The contact pressure between a lip part 21 of the sealing element 19 and the shaft 23 is detected. When the detected pressure becomes equal to a preset value, working fluid is applied on the sealing element 19 in a fluid path 18. The pressure or the flow rate of the working fluid is measured. The presence or absence of a defect in sealing property is judged based on the measured result.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to a method and apparatus for testing the sealability of a sealing element, and particularly to a seal of a sealing element suitable for determining the presence or absence of a sealing defect in an annular sealing element such as an oil seal or packing. This invention relates to a sex testing method and device.

0002

2. Description of the Related Art A sealing element such as an oil seal cannot provide sufficient sealing performance if its lip, which performs its sealing function, becomes defective due to scratches, sink marks, foreign matter, or the like. For this reason, the appearance of the lip portion is inspected.

However, defects cannot be detected sufficiently by visually inspecting the appearance of the lip portion. Therefore, as shown in FIG. 3, a method is adopted in which the presence or absence of defects is determined by a leak test.

[0004] In this inspection method, an oil seal 51 is installed as a sealing element on a shaft 50 that has been finished to have the same dimensions and almost the same sliding surface roughness as the actual shaft, and an upper jig 52 and a lower jig 53 are installed. The oil seal 51 is housed in the chamber 54 formed by the oil seal 51, and a working fluid such as air, water, oil, inert gas, etc. is injected into the chamber 54 from the pressure input port 55, and the oil seal 51 is regulated by the lip portion 56 of the oil seal 51. , and measure the pressure or flow rate of the working fluid leaking from the pressure output port 57 to the atmosphere, or measure the amount of pressure drop due to leakage of the applied pressure, and compare this measured value with a preset value. This is compared with an allowable value, and based on the comparison result, it is determined whether there is a sealing defect.

[0005]

However, in the conventional method, if the diameter of the lip portion 56 of the oil seal 51 varies, the contact pressure between the shaft 50 and the lip portion 56 varies, and the pressure of the working fluid or There is a problem in that errors occur in measured values such as flow rate, making it impossible to perform accurate inspections.

An object of the present invention is to provide a sealing performance testing method for a sealing element, which allows highly accurate testing for the presence or absence of sealing performance defects even if there are variations in the inner diameter of the lip of the annular sealing element to be tested. Our goal is to provide that device.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides, as a first method, a shaft insertion hole of an annular sealing element inserted into a storage chamber, the distal end of which is formed into a tapered part. The contact pressure between the lip of the annular sealing element and the shaft is detected, and when the detected pressure becomes equal to a set value, the position of the shaft is fixed. and an annular sealing element, the pressure or flow rate of the working fluid is measured, and the presence or absence of a sealing defect is determined from the measurement results. was adopted.

[0008] As a second method, the inner diameter of the lip of the annular sealing element is measured, and then the annular sealing element is inserted into the accommodation chamber, and the tip end thereof is inserted into the shaft insertion hole of the annular sealing element. Insert the shafts in sequence, compare the measured values of the shaft outer diameter and lip inner diameter according to the amount of shaft movement, and when the difference between the two becomes equal to the set value, fix the shaft position and After that, a working fluid is injected into the storage chamber and the space between the shaft and the annular sealing element, the pressure or flow rate of the working fluid is measured, and the presence or absence of a sealing defect is determined from the measurement results. This method employs an element sealing test method.

[0009] The first device includes a container having a storage chamber for accommodating an annular sealing element, a fluid passage communicating with the storage chamber, and a shaft insertion passage, and a shaft of the annular sealing element having a tapered portion at the distal end. A shaft that can be inserted into the insertion hole and the shaft insertion path of the container, and the shaft is sequentially inserted from the shaft insertion path of the container into the shaft insertion hole of the annular sealing element in the storage chamber, and the shaft is fixed at a specified position according to a command. contact pressure measuring means that detects the contact pressure between the lip of the annular sealing element and the shaft and outputs a shaft fixing command to the movement control means when the detected pressure becomes equal to a set value; A working fluid measuring means for measuring the pressure or flow rate of the working fluid injected into the fluid passage of the container and the space between the shaft and the annular sealing element, and the presence or absence of sealing defects from the measurement results of the working fluid measuring means. A sealing performance testing device for a sealing element is characterized in that it comprises a determining means for determining the sealing property of a sealing element.

[0010] The second device includes an inner diameter measuring means for measuring the inner diameter of the lip portion of the annular sealing element, a housing chamber for housing the annular sealing element, a fluid passage communicating with the housing chamber, and a container having a shaft insertion passage. a shaft having a tapered portion at its tip and capable of being inserted through the shaft insertion hole of the annular sealing element and the shaft insertion passage of the container; A movement control means that is inserted into a hole sequentially and fixes the shaft at a specified position according to a command, and a measured value of the shaft outer diameter and inner diameter measuring means are compared sequentially as the shaft moves, and the difference between the two is determined as a set value. an interference measuring means for outputting a shaft fixing command to the movement control means when the shaft fixing command becomes equal to A sealing performance testing device for a sealing element is characterized in that it comprises a working fluid measuring means and a determining means for determining the presence or absence of a sealing performance defect from the measurement results of the working fluid measuring means.

[0011]

[Operation] According to the above-described means, the shafts are sequentially inserted into the shaft insertion holes of the annular sealing element, and the position of the shaft is determined when the contact pressure between the lip of the annular sealing element and the shaft becomes equal to a set value. In this state, a working fluid is injected into the space and fluid passage between the shaft and the annular sealing element, and the presence or absence of a sealing defect is determined from the pressure or flow rate of this working fluid. Even if variations occur in the inner diameter of the lip portion, it is possible to prevent errors from occurring in the measured value of the working fluid.

[0012] Also, the inner diameter of the lip of the annular sealing element is measured in advance, and then the shafts are sequentially inserted into the shaft insertion hole of the annular sealing element, and the difference between the shaft outer diameter and the lip inner diameter is equal to the set value. At this point, the position of the shaft is fixed, and in this state, working fluid is injected into the fluid passage and the space between the shaft and the annular sealing element, and the presence or absence of a sealing defect is determined from the pressure or flow rate of the working fluid. Therefore, even if an error occurs in the inner diameter of the lip portion, it is possible to prevent an error from occurring in the measured value of the working fluid.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a container 10 is composed of an upper jig 11 and a lower jig 12, and the upper jig 11 has a shaft insertion passage 13, a pressure input port 14, and a fluid passage 15.
is formed. The lower jig 12 has a pressure output port 16
, and a fluid passage 17 are formed therein, and the upper jig 11 and the lower jig 12 are each formed with a recess that cooperates to form a storage chamber (18).

An oil seal 19 as an annular sealing element is housed in the accommodation chamber 18, and this oil seal 19 has a shaft insertion hole 20 formed on its inner circumferential side and an annular lip portion 21. is formed. Further, an O-ring 22 is installed in the middle of the shaft insertion passage 13, and a shaft 23 is slidably inserted into the shaft insertion passage 13.

The shaft 23 has a tapered portion 24 at its tip, and its rear end is connected to a piston rod 26 via a load cell 25 as a load measuring means, and this piston rod 26 is connected to a piston 28 of a drive device 27. is connected to.

The load cell 25 detects the contact pressure between the shaft 23 and the lip portion 21, converts the load due to this detected pressure into an electrical signal, and outputs the electrical signal to the control device 29. The control device 29 controls the drive of the drive device 27 while monitoring the signal from the load cell 25, and also controls the drive of a brake device (not shown) for restraining the shaft 23.

That is, after outputting a drive command to the drive device 27, when the detected load of the load cell 25 becomes equal to the set value, a shaft fixing command is output to the brake device,
The shaft 23 is fixed at a designated position.

Further, in this embodiment, a working fluid injector (not shown) for injecting working fluid such as air, water, oil, or inert gas into the pressure input port 24 is provided, and the pressure output port 16 A working fluid measuring device (
(not shown) and a determination device (not shown) that determines whether there is a sealing defect based on the measurement results of the working fluid measuring device.

In the above configuration, the storage chamber 1 of the container 10
After the oil seal 19 is accommodated in the oil seal 19 , the shaft 23 is sequentially inserted into the shaft insertion hole 20 of the oil seal 19 from the shaft insertion passage 13 according to commands from the control device 29 . Then, while the shaft 23 is moving, the detection output of the load cell 25 is sequentially monitored, and it is determined whether the detected load of the load cell 25 is equal to a set value.

That is, when the shaft 23 moves with the tapered part 24 of the shaft 23 in contact with the lip part 21, the contact pressure between the shaft 23 and the lip part 21 is proportional to the distance of the shaft 23 as the shaft 23 moves. and increase. When the load detected by the load cell 25 becomes equal to the set value, the brake device is activated to fix the shaft 23 at a specified position.

Thereafter, working fluid is injected into the housing chamber 18 from the pressure input port 14 through the fluid passage 15, and pressure is applied to the oil seal 19. In this state, the pressure or flow rate of the working fluid discharged from the pressure output port 16 is measured, and the presence or absence of a sealing defect is determined based on whether the set value is within the range of allowable values.

As described above, according to this embodiment, the pressure or flow rate of the working fluid is measured when the contact pressure between the shaft 23 and the lip portion 21 becomes equal to the set value, and the sealing is performed based on this measured value. Since the presence or absence of a sealing defect is determined, even if an error occurs in the inner diameter of the lip portion 21, the presence or absence of a sealing defect can be determined with high accuracy.

Next, another embodiment of the present invention will be explained based on FIG. 2. Note that the same members as those in the above embodiment are given the same numbers and detailed explanations will be omitted.

In this embodiment, before the oil seal 19 is housed in the container 10, the inner diameter of the lip portion 21 of the oil seal 19 is measured using a matrix camera 30. In other words, the oil seal 1 is
9 is photographed, the photographed image is image-processed, and the lip portion 2 is
Measure the inner diameter of 1. Then, this measured value is sent to the control device 2.
Output to 9. The control device 29 stores in advance outer diameter information regarding the tapered portion 24 of the shaft 23, and the measured value and the outer diameter of the tapered portion 24 are sequentially compared.

That is, after the oil seal 19 is housed in the container 10, in the process of sequentially inserting the shaft 23 into the shaft insertion hole 20 of the oil seal 19, the tapered portion 24
The difference between the outer diameter of the lip portion 21 and the inner diameter of the lip portion 21 measured by the matrix camera 30 is compared, and when the difference between the two, that is, the tightening distance reaches the set value, the brake device is actuated to move the shaft 23 to the specified position. Fixed in position. After that, similarly to the embodiment described above, the working fluid is injected into the accommodation chamber 18 from the pressure input port 14 to apply the pressure of the working fluid to the oil seal 19, and the pressure of the working fluid discharged from the pressure output port 16 or The flow rate is measured, and based on the measurement results, it is determined whether there is a sealing defect.

In this embodiment as well, since the flow rate or pressure of the working fluid is measured when the difference between the lip portion 21 and the tapered portion 24 reaches a certain tightening margin, the inner diameter of the lip portion 21 Even if an error occurs, the presence or absence of a sealing defect can be determined with high accuracy.

[0028]

[Effects of the Invention] As explained above, according to the present invention,
The sealing performance is inspected when the contact pressure between the lip of the sealing element and the shaft reaches the set value, or the difference between the inner diameter of the lip of the sealing element and the outer diameter of the tapered part of the shaft is constant. Since the sealing property is inspected in this state, the presence or absence of a defect in the sealing property can be determined with high accuracy even if an error occurs in the inner diameter of the lip portion of the sealing element.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the present invention.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

10... Container 11...Upper jig 12...Lower jig 13, 20...Shaft insertion hole 15, 17...Fluid passage 18... Containment room 19...Oil seal 21...Lip part 22...O-ring 23...Shaft 24...Tapered part 25...Load cell 26...Piston rod 27... Drive device 28...Piston 29...control device 30...matrix camera

Claims (4)

[Claims] Claim 1: A shaft (23) having a tapered tip (24) is sequentially inserted into a shaft insertion hole (20) of an annular sealing element (19) inserted into a storage chamber (18). to detect the contact pressure between the lip (21) of the annular sealing element (19) and the shaft (23), and when this detected pressure becomes equal to the set value, the position of the shaft (23) is fixed, and then The storage chamber (18) and the shaft (2
3) A sealing element characterized in that a working fluid is injected into the space between the annular sealing element (19), the pressure or flow rate of the working fluid is measured, and the presence or absence of a sealing defect is determined from the measurement results. Sealing test method. Claim 2: The lip portion (2) of the annular sealing element (19).
1), then insert the annular sealing element (19) into the accommodation chamber (18), and insert the tapered part (24) into the shaft insertion hole (20) of the annular sealing element (19).
), and compare the measured values of the outer diameter of the shaft (23) and the inner diameter of the lip (21) according to the amount of movement of the shaft (23), and the difference between the two is the set value. The position of the shaft (23) is fixed at the time when the position becomes equal to
and an annular sealing element (19), the pressure or flow rate of the working fluid is measured, and the presence or absence of a sealing defect is determined from the measurement results. Sex test method. 3. A storage chamber (18) accommodating an annular sealing element (19), a fluid passageway (1) communicating with the storage chamber (18).
5, 17), and a shaft insertion passageway (13); a shaft insertion hole (20) of an annular sealing element (19) having a tapered portion (21) at the tip end; A shaft (23) that can be inserted into the shaft insertion passage (13) of the container (10);
) is sequentially inserted into the shaft insertion hole (20) of the annular sealing element (19) in the accommodation chamber (18) from the shaft insertion passage (13) of the shaft, and is fixed at a specified position according to a command. means (27, 29) and an annular sealing element (
Contact pressure that detects the contact pressure between the lip portion (21) and the shaft (23) of 19) and outputs a shaft fixing command to the movement control means (27, 29) when this detected pressure becomes equal to a set value. measuring means (25, 29), fluid passages (15, 17) of said container (10) and shaft (
23) and the annular sealing element (19) (18)
A sealing element comprising: a working fluid measuring means for measuring the pressure or flow rate of the working fluid injected into the sealing element; and a determining means for determining the presence or absence of a defect in sealing performance from the measurement results of the working fluid measuring means. Sealing test device. 4. The lip portion (2) of the annular sealing element (19).
1), an inner diameter measuring means (30) for measuring the inner diameter of the housing chamber (18) that accommodates the annular sealing element (19);
A container (10) having fluid passages (15, 17) and a shaft insertion passage (13) communicating with the annular sealing element (18), and a shaft insertion hole of an annular sealing element (19) having a tapered portion (24) at the tip thereof. (20), and a shaft (23) that can be inserted through the shaft insertion passage (13) of the container (10), and a shaft (23) that can be inserted into the shaft insertion passage (13) of the container (10).
The movement control means (2) is sequentially inserted into the shaft insertion hole (20) of the annular sealing element (19) in the storage chamber (18) from 3) to fix the shaft (23) at a specified position according to a command.
7, 29) and the counted value of the shaft outer diameter and inner diameter measuring means are sequentially compared according to the movement of the shaft (23), and when the difference between the two becomes equal to the set value, the shaft fixing command is sent to the movement control means. the fluid passages (15, 17) of the container (10), and the shaft (
23) and the sealing element (19), and a working fluid measuring means for measuring the pressure or flow rate of the working fluid injected into the space (18), and the presence or absence of sealing defects from the measurement results of the working fluid measuring means. 1. A sealability testing device for a sealing element, comprising a determination means for determining.