JP2012026909A - Leak tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leak tester capable of using motor-driven driving means as a driving source of a clamp and achieving space saving and cost saving of the whole apparatus.SOLUTION: A leak tester includes upper/lower clamping means for clamping upper and lower surfaces of a work W and front/rear clamping means for clamping front and rear surfaces of the work W. The upper/lower clamping means includes a portal upper/lower clamp supporting frame 1 on which an upper surface seal plate 7 and a lower surface seal plate 5 are installed. The lower surface seal plate 5 is driven by lift drive means 6 and clamps the work between the lower surface seal plate 5 and the upper surface seal plate 7. The front/rear clamp means includes a portal front/rear clamp supporting frame 21 on which a front seal plate 26 and a rear backup plate 27 are installed. The front seal plate 26 and the rear backup plate 27 are driven so as to be moved in a direction that both the plates 26, 27 approach each other or a direction that both the plates 26, 27 are separated from each other by single motor-driven driving means 29 to clamp the front and rear surfaces of the work.

Description

  The present invention relates to a leak tester, and more particularly to an electric leak tester that has a relatively compact configuration and can be supplied at low cost.

  Many parts such as automobiles and gas appliances require a leak test. In a leak tester that performs this leak test, a masking jig equipped with a masking rubber that adheres closely to each workpiece, which is the part to be inspected, is used to maintain airtightness, and this masking jig is clamped to the workpiece with a cylinder. Then, air is supplied into the workpiece, and the presence or absence of a cast hole in the workpiece is inspected.

  In the conventional leak tester, the workpiece is clamped exclusively by using a hydraulic cylinder as a drive source (see Japanese Patent No. 30842404, Japanese Patent No. 3083370, Japanese Patent No. 2683658, Japanese Patent No. 2527997, etc.) ).

  In other words, the clamp does not cut the pressing force by the cylinder at the clamp end, and it is necessary to maintain the clamp state during the test. However, if this clamping is performed using an electric motor, the clamping state must be maintained with the motor rotating, and the motor is burned out due to overcurrent. For this reason, a hydraulic cylinder is exclusively used as a drive source for conventional clamps, and it has not been considered to use an electric motor as a drive source.

  As described above, in the conventional leak tester, a hydraulic cylinder is exclusively used as a drive source for the clamp, so that a large installation space for a hydraulic unit, a hydraulic manifold block, a hydraulic cylinder, hydraulic piping, and the like is required, which is saved. This hinders space and cost savings.

Japanese Patent No. 30802404 Japanese Patent No. 3082370 Japanese Patent No. 2683658 Japanese Patent No. 2527997

  As described above, in the case of the conventional leak tester, since a hydraulic cylinder is used as a driving source of the clamp, space saving and cost saving are hindered. Therefore, the present invention provides a leak tester that enables electric drive means to be used in place of a hydraulic cylinder as a drive source of a clamp, thereby realizing space saving and cost saving of the entire apparatus. Let it be an issue.

  The invention according to claim 1 for solving the above-mentioned problem comprises upper and lower clamping means for clamping the upper and lower surfaces of the work to be inspected for leakage, and front and rear clamping means for clamping the front and rear faces of the work, The upper and lower clamp means includes a portal-shaped upper and lower clamp support frame configured by connecting the upper ends of a pair of support walls with a frame, and an upper seal plate and a lower seal plate are installed on the upper and lower clamp support frame. The lower surface seal plate is driven up and down by an electric lifting drive means disposed on the support frame for the upper and lower clamps, and the workpiece is clamped between the upper surface seal plate at its rising end, , A gate formed by connecting upper ends of a pair of end frames with an upper surface plate, on the support frame for the upper and lower clamps A front and rear clamp support frame disposed in an intersecting state, wherein the front and rear clamp support frame is provided with a front seal plate and a rear backup plate, and the front seal plate and the rear backup plate are a single electric drive; The front and rear surfaces of the workpiece are clamped at the horizontal movement ends of the front seal plate and the back-up backup plate in the direction close to each other. This is a leak tester.

  In one embodiment, the upper and lower clamp means is such that only the lower seal plate is driven up and down by a servo jack driven by a servo motor, and the upper seal plate is fixed to the upper and lower clamp support frame and does not move. Further, the lower surface seal plate is attached between LM guides engaged with a pair of guide rails installed in parallel in the vertical direction on one inner wall of the support wall of the support frame for the upper and lower clamps, and supports its lifting operation. Is done.

  In one embodiment, the front seal plate and the rear backup plate of the front / rear clamp support frame are respectively connected to lower portions of pivot arms pivotally supported by the end frames, and the pivot arms are By being rotationally driven by the single electric drive means, it moves horizontally in a direction toward or away from each other.

  In one embodiment, the single electric drive means is a synchro cylinder that operates to move the upper end of each of the rotating arms in the opposite direction, and the synchro cylinder has both end portions thereof, It is supported on a movable plate slidably disposed on a pair of guide rails laid on the upper surface plate of the front / rear clamp support frame.

  In one embodiment, the synchro cylinder has a connecting member provided with long holes at both ends thereof, and the rotating arm has a connecting shaft arranged at an upper end thereof passed through the long hole. Accordingly, a pair of stoppers that restrict movement of the synchro cylinder in the horizontal direction are installed on the upper surface plate of the front / rear clamp support frame.

  The present invention is as described above, and the leak tester according to the present invention includes upper and lower clamping means for clamping the upper surface and the lower surface of the workpiece to be inspected for leakage, and front and rear clamping means for clamping the front surface and the rear surface of the workpiece. Since each of the upper and lower clamp means and the front and rear clamp means is driven by the electric drive means, for the hydraulic unit, the hydraulic manifold block, the hydraulic cylinder, the hydraulic piping, etc. as in the case of the conventional hydraulic drive means A large installation space is required, and there is no problem that maintenance is troublesome. With a simple configuration, space saving and cost saving can be realized, and maintenance is easy.

It is a perspective view showing the whole leak tester composition concerning the present invention. It is a perspective view which shows the up-and-down clamp means of the leak tester which concerns on this invention. It is a perspective view which shows the front-back clamp means of the leak tester which concerns on this invention. It is a partial block diagram of the front and rear clamping means of the leak tester according to the present invention. It is a fragmentary sectional view which shows the structural example of the synchro cylinder in the front-and-rear clamp means of the leak tester which concerns on this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of a leak tester according to the present invention. As shown therein, the leak tester according to the present invention is a vertical clamping means for clamping the upper and lower surfaces of a workpiece W to be inspected for leaks. And front and rear clamping means for clamping the front and rear surfaces of the workpiece W.

  As shown in FIGS. 1 and 2, the upper and lower clamping means includes a gate-shaped upper and lower clamping support frame 1 formed by connecting upper ends of a pair of support walls 2 and 3 with a frame 4. A plate (masking jig) 7 and a bottom seal plate (masking jig) 5 are installed. Then, the lower seal plate 5 is driven up and down by an electric lift drive means 6 disposed on the upper and lower clamp support frame 1, and the workpiece W is clamped between the upper end seal plate 7 at its rising end, As in the case, air is supplied into the workpiece W, and the presence or absence of a cast hole is inspected. In general, the inspection air is supplied from the bottom seal plate 5 side.

  A servo jack system using a servo motor 8 is suitable as the elevation drive means 6 for moving the lower seal plate 5 up and down. This system includes a servo motor 8, a speed reducer 9, a servo jack that operates in response to the rotational driving force of the servo motor 8 decelerated via a coupling 10, and a control device that controls the servo motor 8. Composed.

  For example, as a servo jack, a reduction gear 9 and an input shaft 70 that receives a rotational driving force of a servo motor 8 decelerated via a coupling 10 and has a driving bevel gear at the tip thereof facing the gear case 11; A commercially available product comprising a rotating cylinder fitted with a driven bevel gear that meshes with a driving bevel gear, a ball nut incorporated in the rotating cylinder, and a ball screw shaft 12 that passes through the gear case 11 vertically and is screwed into the ball nut. Can be used. In this case, the fixing disk at the upper end of the ball screw shaft 12 is fixed to the back surface of the lower seal plate 5. In the figure, reference numeral 13 denotes a screw shaft cover in which the ball screw shaft 12 moves up and down.

  In the case of this servo jack, the rotating cylinder and the ball nut incorporated therein are rotatably supported, but are restricted from moving in the vertical direction. Accordingly, when the servo motor 8 is operated and the rotational driving force is transmitted from the input shaft into the gear case 11, the rotating cylinder and the ball incorporated therein are driven via the driving / driven bevel gears engaged with each other in the gear case 11. The nut rotates, but the ball nut rotates only at a fixed position and does not move in the vertical direction. Therefore, the ball screw shaft 12 meshing with the nut moves up and down, and the lower seal plate 5 fixed thereto is driven up and down. . And the lower surface seal plate 5 clamps the workpiece | work W between the upper surface seal plate 7 in the raise end, and performs a leak test in the state.

  In a preferred embodiment, the lower surface seal plate 5 is installed on the inner surface of one support wall 2 of the upper and lower clamp support frame 1 so as to be able to move up and down, and is driven up and down by the up and down drive means 6. Is done. That is, the lower surface seal plate 5 is fixed to an elevating plate 17 that is passed between LM guides 16 that engage with a pair of guide rails 15 that are installed on the inner surface of the support wall 2 in parallel in the vertical direction. Normally, the upper surface seal plate 7 is fixed to the back surface of the receiving frame 4 and does not move, and only the lower surface seal plate 5 moves up and down to clamp the workpiece W. Since the clamp pressure generated by the lower seal plate 5 rising is controlled by the control device of the servo motor 8, there is no possibility that excessive pressure is generated or the servo motor 8 is burned out.

  On the other hand, as shown in FIGS. 1 and 3, the front and rear clamping means is configured by connecting upper ends of a pair of end frames 22 and 23 arranged in an orthogonal state on the upper and lower clamping support frame 1 with an upper surface plate 50. A gate-shaped front and rear clamp support frame 21 is provided, and a front seal plate 26 and a rear backup plate 27 are installed on end frames 22 and 23 of the front and rear clamp support frame 21. The front seal plate 26 and the rear backup plate 27 are driven to move horizontally in a direction close to each other or away from each other by a single electric driving means, and the front seal plate 26 and the rear backup plate 27 are mutually moved. The front and rear surfaces of the workpiece W are clamped at the horizontal movement end in the approaching direction.

  The front seal plate 26 and the rear backup plate 27 are respectively connected to lower portions of rotating arms 24 and 25 that are pivotally supported by the end frames 22 and 23, and the rotating arms 24 and 25 are electrically driven driving means. By being rotationally driven by the movement, the horizontal movement is performed in a direction approaching or separating from each other. As the electric driving means used here, a synchro cylinder 29 driven by a servo motor 57 that works to move the upper end portions of the rotary arms 24 and 25 in the opposite direction is recommended.

  The configuration of the front and rear clamping means will be described in more detail. Each of the end frames 22 and 23 is composed of a vertical plate 31 and a side plate 32 provided on the outer side of the vertical plate 31, and the support shaft 35 passes between the side plates 32. The pivot arms 24 and 25 are pivotally supported by the support shaft 35. The rotating arms 24 and 25 are made up of a pair of plate members arranged at an appropriate interval, and the pair of plate members are joined by connecting shafts 36 and 37 between the upper part and the lower part, respectively.

  The synchro cylinder 29 includes connecting members 40 and 41 each having a long hole 39 at both ends, and the rotating arms 24 and 25 have a connecting shaft 36 arranged at the upper end thereof and the length of the connecting members 40 and 41. By being passed through the hole 39, it is connected to the connecting members 40 and 41 (see FIG. 4). Further, the connecting shaft 37 below the pivot arms 24 and 25 is slidably inserted into a long hole 44 formed in the driven plates 42 and 43 extending from the back surfaces of the front seal plate 26 and the rear backup plate 27. The

  A pair of slide bars 46 are installed on the back surfaces of the front seal plate 26 and the rear backup plate 27, and the slide bars 46 are horizontally mounted on bearing units 47 disposed on both sides of the lower side of the vertical plate 31. It is slidably inserted in the direction and supported. The driven plates 42 and 43 are respectively positioned in the middle of the slide bar 46 and extend in parallel with the slide bar 46, extend outward from an opening 49 formed in the lower portion of the vertical plate 31, and have the long hole 44 at the end thereof. Is formed.

  The synchro cylinder 29 is installed on the upper surface plate 50 of the support frame 21 for front and rear clamping. That is, a pair of guide rails 51, 52 are laid on the upper surface plate 50, and the large and small movable plates 54, 55 are disposed across the LM guide 53 engaged with the guide rails 51, 52. A gear case 56, a servo motor 57 that is a driving means for the synchro cylinder 29, a speed reducer 58, and a coupling 59 are installed on the large moving plate 54. On the small moving plate 55, a movable receiving portion 61 that supports an inner tube 64 that is a tip movable portion of the synchro cylinder 29 is installed.

  The synchro cylinder 29 is, for example, as shown in FIGS. 3 and 5, a gear case 56, an outer tube 63 that is fixedly extended to the gear case 56, and an inner tube that is inserted into the outer tube 63. An inner tube 64 that moves forward and backward is configured. A ball screw shaft 65 and a ball nut 66 meshing with the ball screw shaft 65 are incorporated in the inner tube 64. The ball screw shaft 65 is supported so as to rotate without moving in the axial direction, and the ball nut 66 does not rotate. Supported by A bevel gear 69 that meshes with a bevel gear 68 fixed to the input shaft 67 is fixed to the inner end of the ball screw shaft 65.

  The input shaft 67 is connected to a servo motor 57 that is an electric drive source via a coupling 59 and a speed reducer 58. The connecting member 40 is attached to the back surface of the gear case 56, and the connecting member 41 is attached to the tip of the inner tube 64. The movable receiving portion 61 supports the distal end portion of the inner tube 64 and moves following the movement of the inner tube 64.

  In a more preferred embodiment, a pair of stoppers 75 and 76 for restricting the movement of the synchro cylinder 29 in the horizontal direction are installed on the upper surface plate 50 of the front and rear clamp support frame 21. One stopper 75 receives the gear case 56, and the other stopper 76 receives the movable receiving portion 61.

  In performing a leak test in the leak tester according to the present invention having the above-described configuration, first, the workpiece W is set on the lower surface seal plate 5 at the lower end, and the servo motor 8 is operated. As a result, the lower surface seal plate 5 is driven up by the servo jack 11 and is moved up until the upper surface of the workpiece W comes into close contact with the upper surface seal plate 7, and then maintains that state. The upward movement of the lower surface seal plate 5 is supported by an elevating plate 17 that moves up and down along the inner surface of the support wall 2.

  Next, when the servo motor 57 is operated, the ball screw shaft 65 is rotationally driven through the input shaft 67 and the meshing bevel gears 68 and 69. However, since the ball screw shaft 65 rotates but does not move in the axial direction, the ball nut 66 meshing with the ball screw shaft 65 moves in the axial direction of the ball screw shaft 65 as the ball screw shaft 65 rotates. As a result, the inner tube 58 that supports the ball nut 66 so as not to rotate moves forward and backward in the outer tube 57 together with the ball nut 66.

  When the inner tube 58 is retracted, in other words, when the synchro cylinder 29 is contracted, the connecting members 40 and 41 installed at both ends are pulled, and the lengths provided in the connecting members 40 and 41 are extended. The upper portions of the rotary arms 24 and 25 are pulled inward through the connecting shaft 36 inserted through the hole 39. As a result, the pivot arms 24 and 25 pivot so as to form a C shape with the coupling shaft 35 as an axis when the coupling shaft 36 slides in the long hole 39, and the front seal plate 26 and the rear surface The backup plate 27 is separated from each other to enter an unclamped state.

  At that time, the both sides of the synchro cylinder 29 are fixed on the large and small moving plates 54 and 55 and can move. However, in the contraction operation, either one of the stoppers 75 and 76 is concerned due to resistance, balance or the like. First contacts the movable receiving portion 61 or the gear case 56 to stop the movement of the movable receiving portion 61 or the gear case 56. Thereafter, when the contraction operation is further performed, the movable receiving portion 61 side or the gear case 56 side that has not stopped moving further moves further until it comes into contact with the other stoppers 76 and 75.

  Thus, even if any of the movable receiving portion 61 and the gear case 56 comes into contact with the stoppers 75 and 76 first, the movable receiving portion 61 and the gear case 56 finally come into contact with the stoppers 75 and 76, respectively. In this state, the shrinking operation of the synchro cylinder 29 is completed, and accordingly, the turning operations of the turning arms 24 and 25 are also stopped, so that the front seal plate 26 and the rear backup plate 27 are separated from each other by a predetermined distance. It becomes.

  When the servo motor 57 rotates reversely in this unclamped state, the ball screw shaft 65 also rotates reversely. As a result, the inner tube 58 moves forward via the ball nut 66, and the synchro cylinder 29 performs an extending operation. When the synchro cylinder 29 is extended, the connecting members 40 and 41 installed at both ends thereof are pushed outward and the upper portions of the rotating arms 24 and 25 are connected via the connecting shaft 36 inserted through the long hole 39. Are pushed in opposite directions. As a result, the rotating arms 24 and 25 rotate so that the connecting shaft 36 slides in the long hole 39 so that the connecting shaft 35 has an inverted C shape with the connecting shaft 35 as an axis. The plate 26 and the back-up backup plate 27 are close to each other, and the front / rear direction of the workpiece W clamped in the vertical direction is clamped and the state is maintained.

  In this way, while maintaining the clamped state in the vertical direction and the front-rear direction, air is supplied into the workpiece W to inspect for the presence of a cast hole in the workpiece W. The clamping pressure applied to the front and rear surfaces of the workpiece W due to the proximity of the front seal plate 26 and the rear backup plate 27 is controlled by the control device of the servo motor 57 as in the case of the servo motor 8, so that excessive pressure is applied. There is no possibility that the servo motor 57 will burn out.

  Although the present invention has been described in some detail with respect to its most preferred embodiments, it will be apparent that a wide variety of different embodiments can be constructed without departing from the spirit and scope of the invention, the invention being defined by the appended claims. It is not restricted to the specific embodiment other than limiting in.

DESCRIPTION OF SYMBOLS 1 Support frame for upper and lower clamps 2 Support wall 3 Support wall 4 Receiving frame 5 Lower surface seal plate 6 Lifting drive means 7 Upper surface seal plate 8 Servo motor 11 Servo jack 16 LM guide 17 Lift plate 21 Front and rear clamp support frame 22 End frame 23 End Frame 24 Rotating arm 25 Rotating arm 26 Front seal plate 27 Rear backup plate 29 Synchro cylinder 35 Support shaft 36 Connecting shaft 37 Connecting shaft 50 Top plate 53 LM guide 54 Large moving plate 55 Small moving plate 56 Gear case 57 Servo motor 61 Movable receiving part 63 Outer tube 64 Inner tube 75 Stopper 76 Stopper

Claims (8)

Up and down clamping means for clamping the upper and lower surfaces of the workpiece to be inspected for leakage, and front and rear clamping means for clamping the front and rear surfaces of the workpiece,
The upper and lower clamp means includes a gate-shaped upper and lower clamp support frame configured by connecting upper ends of a pair of support walls with a frame, and the upper and lower clamp support frame includes an upper seal plate and a lower seal plate. Installed, the lower surface seal plate is driven up and down by an electric lifting drive means disposed on the support frame for the upper and lower clamps, and clamps the workpiece between the upper surface seal plate at its rising end,
The front-rear clamp means is a portal formed by connecting upper ends of a pair of end frames with an upper surface plate, and includes a front-rear clamp support frame disposed in an orthogonal state on the upper-lower clamp support frame, The front and rear clamp support frame is provided with a front seal plate and a rear backup plate, and the front seal plate and the rear backup plate move horizontally in a direction toward or away from each other by a single electric driving means. The leak tester is characterized in that the front and rear surfaces of the workpiece are clamped at the horizontal movement ends of the front seal plate and the rear backup plate in the direction of approaching each other.   2. The upper and lower clamping means according to claim 1, wherein only the lower seal plate is driven up and down by a servo jack driven by a servo motor, and the upper seal plate is fixed to the upper and lower clamp support frame and does not move. Leak tester.   The lower surface seal plate is installed on the inner surface of one support wall of the upper and lower clamp support frame so as to be able to move up and down, and is driven up and down by the electric lift drive means. The leak tester according to claim 1 or 2.   The front seal plate and the rear backup plate of the front / rear clamp support frame are respectively connected to the lower part of a pivot arm pivotally supported at each end frame, and the pivot arm is the single electric type. The leak tester according to claim 1, wherein the leak tester is horizontally moved in a direction approaching or separating from each other by being rotationally driven by the driving means.   5. The leak tester according to claim 4, wherein the single electric drive means is a synchro cylinder that acts to move the upper end of each of the rotating arms in the opposite direction.   The both ends of the synchro cylinder are supported on separate moving plates that are slidably disposed on a pair of guide rails laid on the upper plate of the support frame for front and rear clamping. Leak tester as described in   The synchro cylinder has a connecting member provided with a long hole at each end thereof, and the rotating arm is connected to the connecting member by passing a connecting shaft arranged at an upper end of the rotating arm through the long hole. The leak tester according to claim 5 or 6.   The leak tester according to any one of claims 5 to 7, wherein a pair of stoppers for restricting movement of the synchro cylinder in the horizontal direction are installed on an upper surface plate of the front / rear clamp support frame.

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