Pressure testing device and pressure testing method

Abstract

To provide a pressure testing device and method capable of setting a cycle of pressurization / depressurization or pressurization to a high frequency and simplifying adjustment work of a stroke amount of a plunger.SOLUTION: In a pressure testing device provided with a liquid supply tube and a vibration mechanism 13A, the vibration mechanism has a drive motor, a cam shaft 16, a rod 17, an arm 18, a link 21 whose one end side is arranged on an intermediate side of each of pivots 35a, 35b of the arm, a plunger, and cylinders. A pressure adjusting nut 38 is pivotally supported on one end side of the link, a pressure adjusting screw 37 is threadedly engaged with the arm and the pressure adjusting nut, the pressure adjusting screw has a projecting part 37a projecting from a surface of the arm, and a stroke amount of the plunger is adjusted by turning the projecting part of the pressure adjusting screw.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pressure test apparatus and a pressure test method, and more particularly to a pressure test apparatus for performing a pressure resistance test on an object to be tested and a pressure test method using the same.

Background Art

[0002] As a conventional pressure test apparatus, one generally known includes a liquid supply pipe connected to a test tank in which an object to be tested is accommodated, and a vibration mechanism that repeatedly increases and decreases the pressure of the liquid filled in the liquid supply pipe and supplied to the test tank (see, for example, Patent Document 1).

[0003] In Patent Document 1, for example, as shown in FIG. 8, the vibration mechanism 113 includes a drive motor 115, a camshaft 116 connected to the drive shaft of the drive motor 115, a rod 117 pivotally supported by the camshaft 116, an arm 118 having one end pivotally supported by the rod 117 and the other end pivotally supported by a fixed side such as a case 119, a link 121 having one end pivotally supported by the arm 118, a plunger 122 connected to the other end of the link 121, and a cylinder 123 having a cylinder chamber 123a into which a liquid F filled in the liquid supply pipe is introduced and in which the plunger 122 reciprocates. It is described that the stroke amount of the plunger 122 is adjusted by changing the pivotal support position of one end of the link 121 with respect to the arm 118. Thereby, the cycle of pressure increase and decrease can be set to a high frequency (for example, 20 to 100 Hz).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the vibration mechanism 113 of Patent Document 1, although the stroke amount of the plunger 122 is adjusted by changing the pivot position of the link 121 with respect to the arm 118, the specific adjustment mechanism has not been studied. Further, in the vibration mechanism 113 of Patent Document 1, since the rear end portion of the plunger 122 is open to the outside, foreign matters such as dust adhering to the plunger 122 may enter the cylinder chamber 123a, and the inner wall of the cylinder chamber 123a may be damaged by the foreign matters, resulting in liquid leakage.

[0006] Note that Patent Document 2 describes a technique for adjusting the eccentricity of an eccentric cam (that is, the stroke amount of a plunger) by replacing shims (see paragraph

[0060] and FIG. 6). However, in the technique of Patent Document 2, it is necessary to prepare a plurality of shims having different thicknesses and replace them, which makes the adjustment work complicated.

[0007] Further, Patent Document 3 describes a technique for adjusting the stroke amount of a plunger by changing the position of a hydraulic pump along a lever (see the 14th line in the upper left column to the 3rd line in the upper right column on page 3 and FIG. 3). However, in order to change the position of the hydraulic pump itself, it is also necessary to change the connection state with the liquid supply pipe, etc., and the adjustment work is still complicated.

[0008] The present invention has been made in view of the above situation, and an object thereof is to provide a pressure test apparatus and a pressure test method capable of setting a cycle of pressure increase / decrease or pressurization at a high frequency and simplifying the adjustment work of the stroke amount of a plunger.

Means for Solving the Problems

[0009] The present invention is as follows. 1. A pressure test apparatus comprising a liquid supply pipe connected to a test object or a test tank in which the test object is accommodated, and a vibration mechanism filled in the liquid supply pipe for repeatedly increasing and decreasing or pressurizing the pressure of the liquid supplied to the test object or the test tank. The vibration mechanism includes a drive motor, a camshaft connected to the drive shaft of the drive motor, a rod pivotally supported on the camshaft, an arm having one end pivotally supported on the rod and the other end pivotally supported on a fixed side, a link disposed on an intermediate side of each pivotal support of the arm, a plunger connected to the other end of the link, and a cylinder having a cylinder chamber connected to the liquid supply pipe and in which the plunger reciprocates. A pressure adjustment nut is pivotally supported on one end side of the link. A pressure adjustment screw is screwed into the arm and the pressure adjustment nut. The pressure adjustment screw has a protruding portion protruding from the surface of the arm. The pressure test apparatus is characterized in that the stroke amount of the plunger is adjusted by rotating the protruding portion of the pressure adjustment screw. 2. The pressure test apparatus according to 1. above, wherein a cover structure is provided on the rear end side of the cylinder to surround the plunger from the outside. 3. A pressure test method characterized by using the pressure test apparatus according to 1. or 2. above.

Effect of the Invention

[0010] According to the present invention, the cycle of increasing and decreasing or pressurizing can be set to a high frequency, and the adjustment work of the stroke amount of the plunger can be simplified. As a result, the pressure resistance test can be efficiently performed.

Brief Description of the Drawings

[0011] The present invention will be further described in the following detailed description by way of non-limiting examples of typical embodiments according to the present invention, with reference to the plurality of drawings referred to, wherein like reference numerals indicate like parts throughout several views of the drawings.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Modes for Carrying Out the Invention

[0012] The matters shown here are exemplary and for exemplarily explaining the embodiments of the present invention, and are described for the purpose of providing an explanation that can most effectively and without difficulty understand the principles and conceptual features of the present invention. In this regard, it is not intended to show the structural details of the present invention to a greater extent than necessary for a fundamental understanding of the present invention, but to clarify for those skilled in the art how some forms of the present invention are actually embodied by the description in combination with the drawings.

[0013] As shown in Fig. 1, the pressure test system 1 according to this embodiment includes a pressure test device 2 for performing a pressure resistance test on a workpiece W (hereinafter also referred to as "workpiece W"). The pressure test system 1 also includes a control unit 3 that controls the processing operations of the pressure test system 1, a liquid tank 4 that stores a liquid F, and a test tank 5 that houses the workpiece W. Note that the type of the workpiece W is not particularly limited. As the liquid F, for example, water, gasoline, light oil, various oils, etc. can be used.

[0014] The pressure test device 2 includes a liquid supply pipe 12 connected to the test tank 5, and a vibration mechanism 13A that is filled in the liquid supply pipe 12 and repeatedly increases and decreases the pressure of the liquid F supplied to the test tank 5. Note that "increasing and decreasing the pressure" is intended to alternately apply pressure increase and pressure decrease to the pressure of the liquid F (such as water pressure, oil pressure, etc.).

[0015] The liquid supply pipe 12 is connected to the liquid tank 4 via a valve 6. A vacuum pump 7 for filling the liquid F in the liquid tank 4 into the liquid supply pipe 12 is connected to the liquid supply pipe 12. A pressure regulating pump 8 for applying pressure to the filled liquid F is connected to the liquid supply pipe 12. Further, a detector 9 for detecting the pressure of the filled liquid F is connected to the liquid supply pipe 12. Each of the pumps 7, 8 and the detector 9 is connected to the control unit 3. Note that the material of the liquid supply pipe 12 is not particularly limited and is determined according to the type of the liquid. For example, a metal pipe, a resin or rubber flexible hose, etc. can be used.

[0016] As shown in Fig. 2, the vibration mechanism 13A includes a drive motor 15 (specifically, an electric motor 15), a camshaft 16 connected to the drive shaft 15a of the drive motor 15, a rod 17 pivotally supported by the camshaft 16, an arm 18 having one end (lower end) pivotally supported by the rod 17 and the other end (upper end) pivotally supported by a fixed side such as the case 19, a link 21 disposed on the intermediate side between the positions of the respective pivots 35a and 35b (see Fig. 3) of the arm 18 at one end, a plunger 22 connected to the other end of the link 21, and a cylinder 23 having a cylinder chamber 23a to which the liquid supply pipe 12 is connected and in which the plunger 22 reciprocates.

[0017] Pulleys 24 are provided on each of the drive shaft 15a of the drive motor 15 and the camshaft 16, and a belt 25 is wound around each pulley 24.

[0018] As shown in Figs. 3 and 4, a disk-shaped cam 27 is provided eccentrically with respect to the axis of the camshaft 16 on the camshaft 16. A bearing 29 for rotatably supporting the outer periphery of the cam 27 is provided on the rod 17.

[0019] The arm 18 includes a first plate member 31 and a pair of second plate members 32, 32 disposed with the first plate member 31 interposed therebetween. The plate members 31, 32, 32 are integrated by means such as bolting and welding. Further, an insertion portion 33 into which one end of the link 21 is inserted is recessed in the first plate member 31. One end (lower end) of the first plate member 31 is pivotally supported 35a by one end of the rod 17. One end (upper end) of each of the second plate members 32, 32 is pivotally supported 35b by a fixed side such as the case 19. A pressure adjusting nut 38 is pivotally supported 35c at one end of the link 21. The positions of the respective pivots 35a to 35c are arranged so as to be substantially in a straight line. Each of the pivots 35a to 35c is rotatably supported about an axis parallel to the axis of the camshaft 16.

[0020] A pressure adjusting screw 37 is screwed into the arm 18 (specifically, the first plate member 31) and the pressure adjusting nut 38. The pressure adjusting screw 37 has a protruding portion 37a that protrudes from the surface (upper surface) of the arm 18. By rotating the protruding portion 37a of the pressure adjusting screw 37, the stroke amount of the plunger 22 (i.e., the magnitude of pressure increase and decrease) can be adjusted. Note that the rotation operation of the protruding portion 37a of the pressure adjusting screw 37 (i.e., the tightening and / or loosening operation of the pressure adjusting screw 37) may be performed by operating a handle provided on the protruding portion 37a or by operating a tool locked to the protruding portion 37a.

[0021] As shown in FIG. 2, the other end side of the link 21 is connected to the rear end side of the plunger 22 via a connecting shaft 40. The connecting shaft 40 includes a first shaft portion 41 and a second shaft portion 42 that are spaced apart in the axial direction, and a connecting portion 43 that connects the first shaft portion 41 and the second shaft portion 42. One screw 44a of a right-handed screw and a left-handed screw is formed on the connecting portion 43 closer to one end, and the other screw 44b is formed on the connecting portion 43 closer to the other end. One screw 44a is screwed into the first shaft portion 41, and the other screw 44b is screwed into the second shaft portion 42. By rotating the connecting portion 43 about the axis, the first and second shaft portions 41 and 42 approach or separate from each other, and the length of the connecting shaft 40 is adjusted. Note that the other end side of the link 21 is pivotally supported by the first shaft portion 41.

[0022] The cylinder chamber 23a of the cylinder 23 is connected to the liquid supply pipe 12 so as to introduce the liquid F filled in the liquid supply pipe 12. Further, a cover structure 46 is provided on the rear end side of the cylinder 23 so as to isolate the plunger 22 from the outside. The cover structure 46 has a pair of opposing walls 47, 47 that oppose each other, and a pipe-shaped peripheral wall 48 provided between the pair of opposing walls 47, 47. A drain port 49 is provided in the peripheral wall 48.

[0023] The pressure regulating pump 8 is a pump for adjusting the median value of the maximum pressure and the minimum pressure in the pressure increase and decrease of the liquid F filled in the liquid supply pipe 12. For example, as shown in FIG. 5(a), when the difference between the maximum pressure and the minimum pressure in the pressure increase and decrease is 30 MPa, without pressurizing by the pressure regulating pump 8, the minimum pressure in the pressure increase and decrease can be set to 0 MPa, the maximum pressure can be set to 30 MPa, and the median value can be set to 15 MPa. On the other hand, for example, as shown in FIG. 5(b), by pressurizing by 5 MPa with the pressure regulating pump 8, the minimum pressure in the pressure increase and decrease can be set to 5 MPa, the maximum pressure can be set to 35 MPa, and the median value can be set to 20 MPa. Alternatively, for example, the minimum pressure in the pressure increase and decrease can be set to -10 MPa, the maximum pressure can be set to 20 MPa, and the median value can be set to 5 MPa.

[0024] Next, the operation and effect of the pressure test apparatus 2 having the above configuration will be described. As shown in FIG. 6, the work W is installed in the test tank 5 (step S1), and the vacuum pump 7 is operated (step S2). At this time, the inside of the liquid supply pipe 12 becomes vacuum due to the closing of the valve 6. Next, the valve 6 is opened, and the liquid F stored in the liquid tank 4 is filled into the liquid supply pipe 12 (step S3). Here, if necessary, the pressure regulating pump 8 is operated to adjust the center height of the minimum pressure and the maximum pressure of the pressure increase and decrease applied to the pressure of the liquid F (step S4).

[0025] Next, the drive motor 15 is driven to start the pressure increase and decrease of the liquid F (step S5). That is, the pressure of the liquid F supplied to the work W by the vibration mechanism 13A is repeatedly increased and decreased. Then, the number of repetitions of the pressure increase and decrease is counted, and it is determined whether or not the test is completed based on whether or not the preset number of completion times has been reached (step S6). As a result, if it is determined that the test is completed, the drive motor 15 is stopped and the process is terminated.

[0026] On the other hand, when it is determined that the test has not ended, during the operation of the pressure test device 2, a detection signal from the detector 9 is received to determine whether the pressure of the test liquid F inside the liquid supply pipe 12 is within a predetermined pressure range (step S7). As a result, when it is determined that the pressure is outside the pressure range, the pressure of the liquid F is feedback-controlled by the pressure regulating pump 8 (step S8). On the other hand, when it is determined that the pressure is not outside the pressure range, or after the pressure regulation by the pressure regulating pump 8, the driving of the drive motor 15 is continued (step S5).

[0027] Also, during the operation of the vibration mechanism 13A, the camshaft 16 rotates due to the driving of the drive motor 15, and the rod 17, the arm 18, and the link 21 swing. As a result, the plunger 22 reciprocates, and the pressure of the liquid F in the cylinder chamber 23a is repeatedly increased and decreased. If the reciprocating speed of the plunger 22 at this time is adjusted to, for example, 50 times per second, the pressure of the liquid F is also increased and decreased 50 times per second. On the other hand, when the vibration mechanism 13A stops, by rotating the protruding portion 37a of the pressure adjustment screw 37, the intervals of the shaft supports 35a to 35c of the rod 17, the arm 18, and the link 21 are changed, and the stroke amount of the plunger 22 is adjusted.

[0028] As described above, according to the pressure test apparatus 2 of the present embodiment, the vibration mechanism 13A includes a drive motor 15, a camshaft 16 connected to the drive shaft 15a of the drive motor 15, a rod 17 pivotally supported by the camshaft 16, an arm 18 having one end pivotally supported by the rod 17 and the other end pivotally supported on the fixed side, a link 21 disposed on the intermediate side between the respective pivot supports 35a and 35b of the arm 18 at one end, a plunger 22 connected to the other end of the link 21, and a cylinder 23 having a cylinder chamber 23a to which the liquid supply pipe 12 is connected and in which the plunger 22 reciprocates. A pressure adjustment nut 38 is pivotally supported on one end side of the link 21, and a pressure adjustment screw 37 is screwed into the arm 18 and the pressure adjustment nut 38. The pressure adjustment screw 37 has a protruding portion 37a protruding from the surface of the arm 18, and the stroke amount of the plunger 22 is adjusted by rotating the protruding portion 37a of the pressure adjustment screw 37. Thereby, the cycle of pressure increase / decrease or pressurization can be set to a high frequency (for example, 20 to 100 Hz), and the adjustment work of the stroke amount of the plunger 22 can be simplified. As a result, the pressure resistance test can be efficiently performed.

[0029] Furthermore, in the present embodiment, a cover structure 46 is provided on the rear end side of the cylinder 23 so as to surround the plunger 22 from the outside. Thereby, it is possible to suppress foreign matters such as dust from adhering to the plunger 22. Therefore, it is possible to suppress the inner wall of the cylinder chamber 23a from being damaged by foreign matters and causing liquid leakage.

[0030] Next, with reference to FIG. 7, the vibration mechanism 13B according to another embodiment will be described, and the same reference numerals are given to substantially the same component parts as those of the above-described vibration mechanism 13A, and detailed description thereof will be omitted.

[0031] This vibration mechanism 13B has a cylinder 23 having a cylinder chamber 23a in which the plunger 22 reciprocates. The cylinder chamber 23a is connected to the liquid supply pipe 12 so as to supply the liquid F introduced from the outside (for example, the liquid tank 4, tap water, etc.) into the cylinder chamber 23a to the liquid supply pipe 12.

[0032] The cylinder 23 is formed with a branched communication passage 51 that communicates the liquid supply pipe 12 and the external liquid F with respect to the cylinder chamber 23a. A discharge-side valve 52 is provided at a portion of the communication passage 51 that communicates the cylinder chamber 23a and the liquid supply pipe 12. The discharge-side valve 52 is constituted by a check valve that allows liquid to flow only in the direction from the cylinder chamber 23a to the liquid supply pipe 12. Further, an intake-side valve 53 is provided at a portion of the communication passage 51 that communicates the cylinder chamber 23a and the external liquid F. The intake-side valve 53 is constituted by a check valve that allows liquid F to flow only in the direction from the external liquid F to the cylinder chamber 23a. By providing these two valves 52 and 53, the liquid F introduced from the outside into the cylinder chamber 23a can be repeatedly supplied to the liquid supply pipe 12 by the reciprocating movement of the plunger 22.

[0033] In addition, in the present invention, the invention is not limited to the above-described embodiment, and various modified embodiments can be adopted within the scope of the present invention according to the purpose and application. That is, in the above-described embodiment, the liquid supply pipe 12 connected to the test tank 5 in which the work W is accommodated is exemplified, but the invention is not limited thereto. For example, the liquid supply pipe 12 may be directly connected to the opening of the tubular, container-shaped, or bag-shaped work W.

[0034] Also, in the above-described embodiment, the liquid F is filled in the liquid supply pipe 12 by evacuation by the vacuum pump 7, but the invention is not limited thereto. For example, the liquid F may be filled in the liquid supply pipe 12 by delivery by a delivery pump.

[0035] Furthermore, in the above-described embodiment, an electric motor is exemplified as the drive motor 15, but the invention is not limited thereto. For example, a hydraulic, hydraulic, or pneumatic motor may be adopted as the drive motor 15.

[0036] The present invention is not limited to the embodiments described in detail above, and various modifications or changes are possible within the scope shown in the claims of the present invention.

Industrial Applicability

[0037] It is widely used as a technology related to the pressure resistance test of the object to be tested.

Explanation of Signs

[0038] 2; Pressure test device 5; Test tank 12; Liquid supply pipe 13A, 13B; Vibration mechanism 15; Drive motor 16; Camshaft 17; Rod 18; Arm 19; Case (fixed side) 21; Link 22; Plunger 23; Cylinder 23a; Cylinder chamber 37; Pressure adjustment screw 37a; Protrusion 38; Pressure adjustment nut 46; Cover structure F; Liquid W; Workpiece (object to be tested).

Claims

1. A pressure test device comprising a liquid supply pipe connected to a test object or a test tank in which the test object is accommodated, and a vibration mechanism filled in the liquid supply pipe for repeatedly increasing and decreasing or pressurizing the pressure of the liquid supplied to the test object or the test tank, wherein the vibration mechanism includes a drive motor, a camshaft connected to the drive shaft of the drive motor, a rod pivotally supported by the camshaft, an arm having one end pivotally supported by the rod and the other end pivotally supported by a fixed side, a link disposed on an intermediate side of each pivotal support of the arm, a plunger connected to the other end side of the link, and a cylinder having a cylinder chamber connected to the liquid supply pipe and in which the plunger reciprocates, a pressure adjustment nut is pivotally supported on one end side of the link, a pressure adjustment screw is screwed into the arm and the pressure adjustment nut, the pressure adjustment screw has a protruding portion protruding from the surface of the arm, and the pressure test device is characterized in that the stroke amount of the plunger is adjusted by rotating the protruding portion of the pressure adjustment screw.

2. The pressure test device according to claim 1, wherein a cover structure is provided on the rear end side of the cylinder to surround the plunger so as to isolate it from the outside.

3. A pressure test method characterized by using the pressure test device according to claim 1 or 2.

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