JP2007307011A - Testing device of condyle ball for artificial hip joints - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To seal the liquid of a high pressure in the stem fitting hole of a condyle ball and to detect a defective condyle ball by performing total inspections. <P>SOLUTION: A sealing means has a first sealing part 33 disposed around a projection part 27 and arranged at the side end part of a parietal part 100a in a liquid pressure chamber 32 and a second sealing part 34 arranged on the side end part of a counter-parietal part 100b, and the first sealing part 33 and the second sealing part 34 respectively seal the part between the projection part 2 and a tapered inner peripheral surface 100d. The first and second sealing parts (33, 34)have ring-like metal seals (35a, 35b) and ring-like resin seals. The respective resin seals are arranged so as to face each other through the liquid pressure chamber 32, and the respective metal seals (35a, 35b) are arranged so as to be adjacent to the respective resin seals on the opposite side of the liquid pressure chamber 32. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an artificial hip joint head ball test apparatus for detecting a defective head ball ball by applying a load to the head head ball used in an artificial hip joint.

  2. Description of the Related Art Conventionally, an artificial hip joint head ball test apparatus for detecting a defective head ball ball by applying a load to the head head ball used in an artificial hip joint is known (Patent Document 1, Non-Patent Document 1). reference). In the test apparatus described in Patent Document 1, the bone head ball is supported by the support member from the parietal side and the non-parietal side. Then, pressure is applied to the inside of the stem fitting hole from the non-parietal side support portion in which the distal end side is fitted into the stem fitting hole that opens on the opposite side of the head of the head to be fitted with the stem used in the artificial hip joint. Water is introduced and a load is applied by this water pressure. And inside the stem fitting hole of the bone head ball, the gap between the inner peripheral surface of the stem fitting hole and the opposite head side support portion is sealed by gaskets arranged one above the other. . Moreover, in the test apparatus described in the nonpatent literature 1, what has arrange | positioned the sleeve made from a plastic between the internal peripheral surface of a stem fitting hole and a counter head part side support part is disclosed. The pressure water is sealed between the sleeve and the non-head-side support portion, and the pressure is transmitted to the inner peripheral surface of the stem fitting hole via the sleeve. ing. By using such a test apparatus, it is conceivable to detect a defective bone head ball by performing 100% inspection regardless of a method of performing a sampling test at a predetermined rate and performing a destructive test.

German Patent Application Publication No. 4411508 Bernhard Weisse, "Improvement of the reliability of ceramic hip joint implants", Journal of Biomechanics 36 (2003) 1633-1639

  In order to detect a defective bone head ball, it is necessary to apply a considerable high load (for example, about 14.2 kN) to the bone head ball. For this reason, the pressure of the liquid sealed inside the stem fitting hole is considerably high. (For example, about 90 MPa) needs to be set. However, since the test apparatus described in Patent Document 1 seals the pressure water with the gasket, the gasket cannot be sufficiently sealed when the pressure becomes high, leading to water leakage or deformation or breakage of the gasket. There is a risk of being invited. Further, in the test apparatus described in Non-Patent Document 1, since pressure water is sealed in a plastic sleeve, when the pressure becomes high, the sleeve is deformed or damaged. Therefore, in these test apparatuses, it is difficult to seal a high-pressure liquid inside the stem fitting hole.

  In view of the above circumstances, the present invention can seal a high-pressure liquid in a stem fitting hole of a bone head ball, and can detect a defective bone head ball by performing 100% inspection. An object of the present invention is to provide a bone head ball testing apparatus.

Means and effects for solving the problems

The present invention relates to an artificial hip joint head ball test apparatus for detecting a defective head ball ball by applying a load to the head head ball used in an artificial hip joint.
In order to achieve the above object, the hip hip head test apparatus according to the present invention has the following characteristics. That is, the present invention comprises the following features alone or in appropriate combination.

  In order to achieve the above object, a hip head ball test apparatus for artificial hip joints according to the present invention is fitted with a head side support device for supporting the head ball from the top side and a stem used in the hip joint. As described above, the front end side is inserted into a stem fitting hole having a tapered inner peripheral surface and opened on the side opposite to the top of the bone head ball, and a pressure liquid is introduced. An anti-head portion side support portion that forms a hydraulic pressure chamber formed between the periphery of the protruding portion and the tapered inner peripheral surface; and the hydraulic pressure chamber disposed around the protruding portion. A first seal portion disposed at an end portion on the top side of the head and a second seal portion disposed on an end portion on the opposite side of the fluid pressure chamber, the first seal portion and the second seal. Each of the projecting portion and the tapered inner peripheral surface A sealing means for sealing the space between the pressure sealing means and a pressure liquid supplying means for supplying a pressure liquid to the hydraulic pressure chamber, wherein each of the first sealing portion and the second sealing portion is a ring formed of a metal material. A ring-shaped resin seal formed of a resin material, and the resin seals are arranged so as to face each other through the hydraulic chamber, and the metal seals are arranged in the resin seals. The hip head ball test apparatus for artificial hip joints is arranged so as to be adjacent to the opposite side of the hydraulic chamber.

  According to this configuration, the pressure liquid supplied to the hydraulic chamber formed between the tapered inner peripheral surface of the stem fitting hole in the bone head ball and the projecting portion of the opposite head side support portion is the hydraulic chamber. It is sealed by a sealing means having a first seal portion disposed at the end portion on the top side of the head and a second seal portion disposed at the end portion on the side opposite to the top of the head. Each of the first and second seal portions includes a resin seal disposed on the inner side (hydraulic pressure chamber side) and a metal seal disposed on the outer side (opposite side of the hydraulic pressure chamber with respect to the resin seal). It is configured with. For this reason, while being able to exhibit high followability with respect to the surface to be sealed by disposing a resin seal that is easily deformed, a sealing member having high strength by disposing a high-strength metal seal on the outside The function as can also be demonstrated. In this way, the multi-layer structure of the inner resin seal and the outer metal seal makes the resin seal deform and seal the pressure liquid at low pressure, and the metal seal deforms and seals the pressure liquid at high pressure. Therefore, the pressure liquid can be steadily sealed over a wide pressure range from low pressure to high pressure. Therefore, according to the configuration of the present invention, a high-pressure liquid can be sealed in the stem fitting hole of the bone head ball, and a test apparatus capable of detecting a defective bone head ball by performing 100% inspection is obtained. Can do.

  A second feature of the hip hip head test apparatus according to the present invention is that the resin seal includes a first resin seal disposed on the hydraulic pressure chamber side, the first resin seal, and the metal seal. It is comprised including the 2nd resin seal arrange | positioned between.

  According to this configuration, the pressure seal can be sealed corresponding to a wider pressure range in the resin seal by further providing the resin seal with a multilayer structure. That is, since the first resin seal can be formed of a resin having a lower deformation resistance and the second resin seal can be formed of a resin having a higher deformation resistance, the first resin seal can be formed when the pressure of the pressure liquid in the hydraulic chamber is low. The resin seal is deformed to seal the pressure liquid, and when the pressure is moderate, the second resin seal is deformed to seal the pressure liquid. For this reason, the sealing function of a pressure liquid can be exhibited uniformly over a wide pressure range.

  A third feature of the hip hip head test apparatus according to the present invention is that the first resin seal is formed such that a cross section perpendicular to the circumferential direction is a circular cross section, and the second resin seal is That is, the cross section perpendicular to the direction is formed to be a rectangular cross section.

  According to this configuration, the first resin seal having a circular cross section that is more easily deformed is disposed on the inner side, and the second resin having a rectangular cross section that is more difficult to deform than the first resin seal between the first resin seal and the metal seal. A seal is placed. For this reason, when the pressure is low, the first resin seal is easily deformed to easily seal the pressure liquid, and when the pressure is moderate, the second resin seal is easily deformed to easily seal the pressure liquid. Therefore, the sealing function of the pressure liquid can be exhibited evenly over a wide pressure range.

  According to a fourth aspect of the test apparatus for a femoral head ball for an artificial hip joint according to the present invention, each of the metal seals has a tapered sealing surface formed on an inner peripheral side thereof, and the tapered seal with respect to the protruding portion. It is characterized by contacting at the surface.

  According to this configuration, since each metal seal abuts against the projecting portion at the tapered seal surface, when the pressure liquid pressure acts through the resin seal, the metal seal is pressed against the projecting portion through the tapered seal surface. However, it becomes easy to adhere to the protruding portion and the tapered inner peripheral surface of the stem fitting hole, and it becomes easier to seal a higher pressure liquid.

  A fifth feature of the hip hip head test apparatus according to the present invention is that the projecting portion forms a hydraulic chamber between the tapered inner peripheral surface and the base portion and the base portion. And the metal seal of the first seal portion is in contact with the edge portion of the head portion of the bolt at the tapered seal surface.

  According to this configuration, the sealing means can be easily attached to the protruding portion by screwing the bolt into the base portion after mounting the first seal portion and the second seal portion around the base portion. And the edge part of the head part of a volt | bolt can be utilized effectively, and it can be made to contact | abut with the taper-shaped sealing surface of the metal seal of a 1st seal part.

  The sixth feature of the hip hip head test apparatus according to the present invention is characterized in that the fluid pressure chamber is disposed between the first seal portion and the second seal portion and abuts on the resin seals. A spacer member for regulating a relative distance between the first seal portion and the second seal portion is further provided.

  According to this configuration, the relative distance between the first seal portion and the second seal portion can be reliably maintained by providing the spacer member that is disposed between the first and second seal portions and contacts the respective resin seals. For this reason, it can prevent that the position of the 1st and 2nd seal part shifts especially when attaching a head ball to the testing device of the present invention.

  The seventh feature of the hip hip head test apparatus according to the present invention is that the spacer member has a cylindrical portion having an outer periphery and an inner periphery that are each formed as a tapered surface, and both end portions are the resin seals. It is formed as a taper ring which contacts with.

  According to this configuration, since the spacer member is formed as a taper ring, the spacer can be stably disposed in the hydraulic chamber formed between the periphery of the projecting portion and the tapered inner peripheral surface of the stem fitting hole. The member can be formed in a simple shape.

  An eighth feature of the hip hip head test apparatus according to the present invention is that the pressure liquid supply means is connected to the pump for discharging the pressure liquid and passes through the protruding portion. And a pressure liquid passage communicating with the fluid pressure chamber between the first seal portion and the second seal portion.

  According to this configuration, the pressure liquid discharged from the pump is supplied to the hydraulic pressure chamber via the pressure liquid passage formed so as to pass through the inside of the protruding portion. For this reason, by providing such a simple pressure liquid passage in the projecting portion, means for supplying high pressure liquid to the hydraulic chamber can be easily realized.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention can be widely applied as a test device for a hip head ball for an artificial hip joint for applying a load to a head ball used in an artificial hip joint to detect a defective head ball.

  First, the hip head ball for an artificial hip joint to be tested by the test apparatus according to the present embodiment will be described. FIG. 6 is a front view illustrating the head ball 100 and the stem 101 used in the artificial hip joint. The bone head ball 100 is formed such that the crown 100a side has an outer shape constituting a part of a spherical surface. The pelvic ball 100 is placed in the pelvis and fitted into a cup (not shown) having an inner surface formed so as to constitute a part of a spherical surface. Stem 101 is formed as a femoral component that is implanted in the proximal portion of the femur (not shown). Further, the bone head ball 100 is formed with a stem fitting hole 100c that opens on the side opposite to the crown 100a on the side opposite to the crown 100a. The stem fitting hole 100c is an end of the stem 101 on the proximal side. (Neck part) is fitted. As well shown in the cutaway sectional view of the head ball 100 in FIG. 5, the stem fitting hole 100c has a tapered inner peripheral surface 100d.

  FIG. 1 is a front view illustrating a hip joint head test apparatus 1 for hip joints according to an embodiment of the present invention (hereinafter simply referred to as “test apparatus 1”), and FIG. 2 is a side view thereof. 1 and 2 includes a base case 11, a motor 12, a lift drive device 13, a pump unit 14, a control unit 15, a controller 16, a support unit 18, and the like. The motor 12, the elevating drive device 13, and the support unit 18 are arranged on the front side of the base case 11, and the pump unit 14, the control unit 15, and the controller 16 are arranged inside the base case 11. Yes.

  As shown in FIGS. 1 and 2, the motor 12 is connected to an elevating drive device 13 configured as a screw mechanism, and a support table 25 attached to the upper end portion of the elevating drive device 13 by the rotation of the motor 12. Ascending and descending operations are performed in the vertical direction. 1 and 2, the state before the lifting drive device 13 performs the ascending operation and the state where the ascending operation is performed to raise the support table 25 in the direction of the arrow (A) in FIG. 1 (in FIG. 1). Both are indicated by a solid line and indicated by a two-dot chain line in FIG.

  As shown in FIG. 2, the pump unit 14 includes a pump 17 that pressurizes water sucked from a tank (not shown) and supplies it as pressure water (pressure liquid). The pressure water supplied from the pump 17 is The non-head-side support portion 20 of the support unit 18 to be described later is supplied via the water pipe 26. FIG. 3 shows a block diagram of the test apparatus 1. As shown in FIGS. 2 and 3, a path for supplying water from the pump 17 to the support unit 18 (in FIG. A water pressure meter 24 for detecting the water pressure of the pressure water is provided in the water pipe 26 (shown). The water pressure detection signal detected by the water pressure meter 24 is input to the controller 16 through the signal line 29.

  As shown in FIG. 3, the control unit 15 includes a pump control device 21 and a motor control device 22. The pump control device 21 controls the pressure of the pressure water discharged from the pump 17 by controlling, for example, the number of rotations of a pump motor (not shown) driving the pump 17 based on a command input from the controller 16. It is supposed to be. The motor control device 22 is configured to control the rotation of the motor 12 based on a command input from the controller 16. Thus, the lifting operation of the lifting drive device 13 in which the screw shaft is connected to the motor 12. Is to control.

  As shown in FIGS. 1 and 2, the support unit 18 includes a parietal side support 19 and an anti-parietal side support 20, and the parietal side support 19 and the anti-parietal side support are provided. The bone head ball 100 used for the test in the test apparatus 1 is supported between the head 20 and the test head 1. The head-side support 19 is disposed on the support table 25 at the upper end of the lifting drive device 13, and the non-equal-top support 20 is attached to a bracket 31 attached to the upper part of the base case 11. In addition, with the head ball 100 supported by the support unit 18, the rotation of the motor 12 is controlled to drive the lifting drive mechanism 13 in the upward direction, thereby applying a load to the head ball 100 supported by the support unit 18. Can be done. A load cell 23 is disposed below the support table 25. The load cell 23 detects a load acting on the head ball 100 between the support table 25 and the bracket 31, that is, between the parietal side support 19 and the non-parietal side support 20. Can be done. A load detection signal detected by the load cell 23 is input to the controller 16 via the signal line 30.

  FIG. 4 shows a cross section of the support unit 18 (a part is shown by a cut-out cross section). As shown in the cross-sectional view of FIG. 4, a conical recess 19a is formed on the top surface of the parietal support 19, and the crown of the bone head ball 100 with respect to the inner peripheral surface of the conical recess 19a. With the abutment on the 100a side, the bone head ball 100 is supported from the parietal part side with respect to the parietal part support part 19. Further, the opposite head-side support portion 20 is provided with a projecting portion 27 at the tip portion thereof. The projecting portion 27 is inserted into the stem fitting hole 100 c of the head ball 100 at the tip side thereof so as to support the head head ball 100. The counter head support portion 20 forms a hydraulic chamber 32 into which pressure water is introduced between the periphery of the projecting portion 27 and the tapered inner peripheral surface 100d. A water supply passage 28 connected to the water pipe 26 is formed in the projecting portion 27, and pressure water is supplied to the hydraulic pressure chamber 32 through the water supply passage 28.

  The controller 16 shown in FIGS. 2 and 3 is configured using, for example, a general-purpose personal computer, and includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and a hard disk (HD). The input / output circuit is provided. The controller 16 receives the load detection signal described above from the load cell 23, and outputs the motor 12 to the motor controller 22 so that the motor 12 is driven until a predetermined load is reached based on the load detection signal. A command will be input. Further, the controller 16 receives the above-described water pressure detection signal from the water pressure meter 24, and pumps the pump 17 to the pump control device 21 so that the pump 17 is driven until a predetermined water pressure is reached based on the water pressure detection signal. 17 output commands are input.

  Next, the configuration of the projecting portion 27 and the vicinity thereof will be described in more detail. FIG. 5 is an enlarged view including a partially cutaway cross section in the vicinity of the projecting portion 27. As shown well in FIG. 5, the projecting portion 27 has a base portion 27a that forms a hydraulic pressure chamber 32 with the tapered inner peripheral surface 100d of the head ball 100, and a distal end side of the base portion 27a. And a bolt 27b to be screwed together.

  Further, the test apparatus 1 is provided with sealing means disposed around the protruding portion 27. This sealing means includes a first seal portion 33 disposed at the end on the top side of the hydraulic chamber 32 and a second seal portion 34 disposed at the end on the side opposite to the top of the hydraulic chamber 32. The first seal portion 33 and the second seal portion 34 are configured to seal between the projecting portion 27 and the tapered inner peripheral surface 100d, respectively.

  The first seal portion 33 includes a metal seal 35a and a resin seal made up of a first resin seal 36a and a second resin seal 37a. The second seal portion 34 includes a metal seal 35b and a resin seal made up of a first resin seal 36b and a second resin seal 37b. These seals (35a, 35b, 36a, 36b, 37a, 37b) are all disposed so as to be in close contact with the periphery of the projecting portion 27. The metal seal 35a and the metal seal 35b are formed of a metal material (for example, copper or steel), and are formed in a ring shape (annular shape). The first resin seals (36a, 36b) and the second resin seals (37a, 37b) are formed of a resin material, and are formed in a ring shape (annular shape). The first resin seal (36a, 36b) is made of, for example, polyethylene, and the second resin seal (37a, 37b) is made of, for example, silicon rubber. The first resin seals (36a, 36b) are formed so that the cross section perpendicular to the circumferential direction is a circular cross section, and the second resin seals (37a, 37b) are rectangular in cross section perpendicular to the circumferential direction. It is formed to have a cross section.

  Further, the resin seals (36 a, 37 a) of the first seal portion 33 and the resin seals (36 b, 37 b) of the second seal portion 34 are arranged so as to face each other with the hydraulic chamber 32 interposed therebetween. The metal seal 35a of the first seal portion 33 is disposed adjacent to the resin seal (36a, 37a) on the opposite side of the hydraulic chamber 32, and the metal seal 35b of the second seal portion 34 is resin. It arrange | positions so that it may adjoin on the opposite side of the hydraulic chamber 32 with respect to a seal | sticker (36b, 37b). The first resin seal 36a of the first seal portion 33 and the first resin seal 36b of the second seal portion 34 are respectively disposed on the hydraulic pressure chamber 32 side. The second resin seal 37a of the first seal portion 33 is disposed between the first resin seal 36a and the metal seal 35a, and the second resin seal 37b of the second seal portion 34 is disposed between the first resin seal 36b and the metal seal. 35b.

  The metal seals 35a and 35b each have a tapered sealing surface 39 formed on the inner peripheral side thereof. Metal seals ((35a, 35b) are arranged so that each of these tapered sealing surfaces 39 abuts against the projecting portion 27. The metal seal 35a of the first seal portion 33 is formed by the bolt 27b. The taper-shaped sealing surface 39 abuts against the edge portion of the head.

  Further, the test apparatus 1 includes a spacer member 38 disposed around the protruding portion 27 as shown in FIG. The spacer member 38 is disposed between the first seal portion 33 and the second seal portion 34 in the hydraulic pressure chamber 32. The spacer member 38 is in contact with the first resin seal 36 a of the first seal portion 33 and the second resin seal 36 b of the second seal portion 34, thereby the first seal portion 33 and the second seal The relative distance from the portion 34 is regulated. The spacer member 38 has a cylindrical portion (a cylindrical portion in which the outer periphery and the inner periphery are formed as conical surfaces) each having a tapered surface on the outer periphery and the inner periphery, and both ends are sealed with the first resin. It is formed as a taper ring that comes into contact with 36a and the first resin seal 36b. The spacer member 38 can be formed of, for example, steel (stainless steel or the like).

  The water supply passage 28 connected to the pump 17 through the water pipe 26 passes through the inside of the projecting portion 27 and the first seal portion 33 with respect to the hydraulic pressure chamber 32 as shown in FIG. The pressure liquid passage of the present embodiment communicating with the second seal portion 34 is configured. Further, the pump 17, the water pipe 26, and the water supply passage 28 constitute the pressure liquid supply means of this embodiment that supplies pressure water (pressure liquid) to the hydraulic pressure chamber 32.

  Next, a test method of a test (hereinafter referred to as a proof test) for detecting a defective head ball by applying a load to the head ball 100 by the test apparatus 1 described above will be described. In the case of performing a proof test, first, the elevation drive device 13 is driven to raise the support table 25 to a predetermined position, so that the distal end side of the projecting portion 27 is inserted into the stem fitting hole 100d. The ball 100 is mounted on the protruding portion 27 from the side opposite to the top 100b. Then, the head-side support tool 19 is placed on the support table 25, and the height of the support table 25 is adjusted so that the bone head ball 100 comes into contact with the conical recess 19a of the head-side support tool 19. In this state, a load can be applied to the bone head ball 100 by the motor 12.

  In the proof test, first, the motor 12 is driven based on a command from the controller 16 to apply a preliminary load to the bone head ball 100. Then, under the condition that the preliminary load is applied, the hydraulic pressure water based on the command from the controller 16 starts to be supplied from the pump 17 to the hydraulic chamber 32 through the water pipe 26 and the water supply passage 28. At this time, since the hydraulic pressure in the hydraulic chamber 32 acts on the bone head ball 100 via the tapered inner peripheral surface 100d, the bone head ball 100 passes in the vertical direction (the center line direction of the bone head ball 100 and passes through the crown 100a). The load in the direction to be applied) will act. After starting the introduction of the pressure water into the hydraulic pressure chamber 32, the pump 17 is controlled so as to gradually increase the water pressure until a predetermined water pressure is reached based on a command from the controller 16, and correspondingly. While controlling the motor 12, a load corresponding to a predetermined load (for example, 14.2 kN) is generated. While the hydraulic pressure is applied to the hydraulic chamber 32 in this way, the periphery of the projecting portion 27 and the tapered inner periphery are formed by the sealing means configured to include the first seal portion 33 and the second seal portion 34. The space between the surface 100d is sealed. After reaching a predetermined load, the state is maintained for a predetermined time, and if the bone head ball 100 is not damaged such as a crack, the proof test is passed.

  According to the test apparatus 1 described above, the hydraulic pressure chamber 32 formed between the tapered inner peripheral surface 100d of the stem fitting hole 100c in the bone head ball 100 and the projecting portion 27 of the anti-head-side support portion 20 is provided. The supplied pressure water is sealed by a sealing means having a first seal portion 33 disposed at the end on the top side of the fluid pressure chamber 32 and a second seal portion 34 disposed on the end on the side opposite to the top of the head. Will be. Each of the first seal part 33 and the second seal part 34 includes a resin seal (36a, 36b, 37a, 37b) disposed on the inner side (the hydraulic pressure chamber 32 side) and an outer side (liquid relative to the resin seal). A metal seal (35a, 35b) disposed on the side opposite to the pressure chamber 32 is provided. For this reason, while being able to exhibit the high followability with respect to the sealing object surface by arrange | positioning the resin seal which is easy to deform | transform inside, it is high intensity | strength by arrange | positioning a strong metal seal (35a, 35b) on the outside The function as a sealing member provided with can also be exhibited. In this way, by forming a multi-layer structure of the inner resin seal and the outer metal seal (35a, 35b), the resin seal is deformed at low pressure to seal the pressure water, and at high pressure the metal seal (35a, 35b). Since the pressure water can be sealed by deforming 35b), the pressure water can be steadily sealed over a wide pressure range from low pressure to high pressure. Therefore, according to the test apparatus 1, high-pressure water can be sealed in the stem fitting hole 100c of the bone head ball 100, and a test apparatus that can detect a defective bone head ball by performing 100% inspection is obtained. Can do.

  Further, according to the test apparatus 1, the pressure seal can be sealed corresponding to a wider pressure range in the resin seal by further providing the resin seal with a multilayer structure. That is, the first resin seal (36a, 36b) is formed of a resin having a lower deformation resistance (for example, silicon rubber described in the present embodiment), and the second resin seal (37a, 37b) is higher in the deformation resistance. Since it can be formed of a resin (for example, polyethylene described in the present embodiment), when the pressure of the pressure water in the hydraulic chamber 32 is low, the first resin seal (36a, 36b) is deformed to generate the pressure water. When the pressure is moderate, the second resin seal (37a, 37b) is deformed to seal the pressure water. For this reason, the sealing function of pressure water can be exhibited uniformly over a wide pressure range.

  Moreover, according to the test apparatus 1, the 1st resin seal (36a, 36b) of the circular cross section which is easy to deform | transform inside is arrange | positioned inside, This 1st resin seal (36a, 36b) and a metal seal (35a, 35b) The second resin seals (37a, 37b) having a rectangular cross section, which are less deformable than the first resin seals (36a, 36b), are disposed between the first resin seals (36a, 36b). For this reason, the first resin seal (36a, 36b) is deformed when the pressure is low, and it is easy to seal the pressure water, and the second resin seal (37a, 37b) is deformed when the pressure is moderate, It becomes easy to seal. Therefore, the sealing function of pressure water can be exhibited evenly over a wide pressure range.

  Further, according to the test apparatus 1, each metal seal (35a, 35b) comes into contact with the projecting portion 27 at the tapered seal surface 39. Therefore, when the pressure water pressure acts through the resin seal, the taper seal While being pressed against the projecting portion 27 via the surface 39, the projecting portion 27 and the tapered inner peripheral surface 100d of the stem fitting hole 100c are easily brought into close contact with each other, and higher pressure water can be easily sealed. .

  Further, according to the test apparatus 1, the first sealing portion 33 and the second sealing portion 34 are mounted around the base portion 27a, and then the bolt 27b is screwed to the base portion 27a so that the sealing means can be easily provided with the protruding portion 27. Can be attached to. And the edge part of the head part of the volt | bolt 27b can be contact | abutted with the taper-shaped sealing surface 39 of the metal seal 35a of the 1st seal | sticker part 33 effectively.

  Further, according to the test apparatus 1, the first seal portion 33 and the second seal portion 34 are provided by providing the spacer member 38 that is disposed between the first seal portion 33 and the second seal portion 34 and contacts the resin seals. The relative distance can be reliably maintained. For this reason, it can prevent that the position of the 1st seal | sticker part 33 and the 2nd seal | sticker part 34 slip | deviates especially when attaching the head ball | bowl 100 to the test apparatus 1. FIG.

  Further, according to the test apparatus 1, since the spacer member 38 is formed as a tapered ring, a hydraulic chamber formed between the periphery of the projecting portion 27 and the tapered inner peripheral surface 100d of the stem fitting hole 100c. It is possible to form the spacer member 38 that can be stably disposed on the plate 32 with a simple shape.

  Further, according to the test apparatus 1, the pressure water discharged from the pump 17 is supplied to the hydraulic pressure chamber 32 through the water supply passage 28 formed so as to pass through the inside of the protruding portion 27. For this reason, by providing such a simple water supply passage 28 in the projecting portion 27, means for supplying high pressure water to the hydraulic chamber 32 can be easily realized.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the pressure liquid may be other than pressure water. Further, the resin seal may not have a multilayer structure. The spacer member may have another shape or may not be provided. Further, the cross-sectional shape and material type of the metal seal and the resin seal may be changed as appropriate.

  INDUSTRIAL APPLICABILITY The present invention can be widely applied as a test device for a hip head ball for an artificial hip joint for applying a load to the head ball used in an artificial hip joint and detecting a defective head ball.

It is a front view which illustrates the testing device of the bone head ball for artificial hip joints concerning one embodiment of the present invention. It is a side view of the testing apparatus of the femoral head ball for artificial hip joints shown in FIG. It is a block diagram of the testing apparatus of the femoral head ball for artificial hip joints shown in FIG. It is sectional drawing of the support unit with which the test apparatus of the hip head ball | bowl for artificial hip joints shown in FIG. FIG. 5 is an enlarged view including a partially cutaway cross section in the vicinity of the protruding portion of the support unit shown in FIG. 4. It is a front view which illustrates the head ball and stem used in an artificial hip joint.

Explanation of symbols

1 Bone head ball testing device for artificial hip joints 17 Pump (pressure liquid supply means)
19 head top side support tool 20 counter head top side support part 27 projecting part 28 water supply passage (pressure liquid supply passage, pressure liquid supply means)
32 Hydraulic chamber 33 First seal portion 34 Second seal portions 35a and 35b Metal seals 36a and 36b First resin seal (resin seal)
37a, 37b Second resin seal (resin seal)
100 Bone head ball 100a Parietal portion 100b Non-parietal portion 100c Stem fitting hole 100d Tapered inner peripheral surface 101 Stem

Claims (8)

A test device for a hip head ball for an artificial hip joint for applying a load to a head ball used in an artificial hip joint to detect a defective head ball,
A parietal side support that supports the bone head ball from the parietal side;
The front end side is inserted into a stem fitting hole having a tapered inner peripheral surface so as to be fitted to a stem used in the artificial hip joint so as to be fitted to a stem head side of the bone head ball to support the bone head ball. A head-side support portion that has a projecting portion and forms a hydraulic chamber into which pressure liquid is introduced between the periphery of the projecting portion and the tapered inner peripheral surface;
A first seal portion disposed around the projecting portion and disposed at an end portion on the top side of the hydraulic chamber and a second portion disposed on an end portion on the opposite side of the hydraulic chamber. Sealing means, wherein the first seal part and the second seal part respectively seal between the projecting part and the tapered inner peripheral surface;
Pressure liquid supply means for supplying pressure liquid to the hydraulic chamber;
With
Each of the first seal portion and the second seal portion includes a ring-shaped metal seal formed of a metal material and a ring-shaped resin seal formed of a resin material, and each of the resin seals is the liquid seal. It is arranged so as to face each other through a pressure chamber, and each of the metal seals is arranged to be adjacent to each of the resin seals on the opposite side of the hydraulic pressure chamber. Bone head ball testing device.   The resin seal includes a first resin seal disposed on the hydraulic chamber side, and a second resin seal disposed between the first resin seal and the metal seal. The test apparatus for a head bone ball for an artificial hip joint according to claim 1.   The first resin seal is formed so that a cross section perpendicular to the circumferential direction is a circular cross section, and the second resin seal is formed so that a cross section perpendicular to the circumferential direction is a rectangular cross section. The test apparatus for a head bone ball for an artificial hip joint according to claim 2.   4. Each of the metal seals has a tapered sealing surface formed on an inner peripheral side thereof, and abuts the protruding portion with the tapered sealing surface. A test apparatus for a head bone ball for an artificial hip joint according to claim 1. The projecting portion has a base portion that forms the hydraulic chamber with the tapered inner peripheral surface, and a bolt that is screwed into the base portion from the tip side thereof,
5. The test device for a femoral head ball for an artificial hip joint according to claim 4, wherein the metal seal of the first seal portion abuts against an edge portion of a head portion of the bolt at the tapered seal surface.   A spacer that is disposed between the first seal portion and the second seal portion in the hydraulic pressure chamber, contacts the resin seals, and regulates a relative distance between the first seal portion and the second seal portion. The apparatus for testing a femoral head ball for an artificial hip joint according to any one of claims 1 to 5, further comprising a member.   7. The spacer member according to claim 6, wherein the spacer member has a cylindrical portion whose outer periphery and inner periphery are each formed as a tapered surface, and both end portions are formed as a tapered ring that contacts the resin seals. The test apparatus of the bone-head ball for artificial hip joints as described.   The pressure liquid supply means includes a pump that discharges the pressure liquid, and the first seal portion and the second seal portion that are connected to the pump and pass through the projecting portion to the hydraulic chamber. And a pressure liquid passage that communicates with the hip joint head ball testing apparatus according to any one of claims 1 to 7.

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