JP2008275003A - Stud bolt mounting structure and booster using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stud bolt mounting structure having less-dispersed fastening strength, highly accurate air-tightness, a reduced defective fraction, improved productivity, and cost effects, and to provide a booster using the same. <P>SOLUTION: The stud bolt 1 comprises a bolt head part 2, a bolt shoulder part 3 having a smaller diameter than the bolt head part 2, and a screw part 4b having a smaller diameter than the bolt shoulder part 3. The bolt shoulder part 3 consists of a knurled portion 3b at least part of which is bitten into a container 10 during caulking and which has a protruded portion 3b<SB>1</SB>and a groove portion 3b<SB>2</SB>on and in the outer periphery, and a bolt base portion 3a which is located between the knurled portion 3b and the bolt head part 2 and whose diameter is gradually larger as tending from the side of the knurled portion 3b to the side of the bolt head part 2. The container 10 has a first member 11 and a second member 12. The first member 11 and the second member 12 each have a hole through which a stud bolt 1 passes. A diameter D11 of the hole 11a of the first member 11 is formed almost the same as or somewhat larger than the diameter of the knurled portion 3b, and a diameter D12 of the hole 12a of the second member 12 is formed almost the same as or somewhat larger than the diameter of the base portion 3a at the side of the bolt head part 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention belongs to the technical field of stud bolts, and in particular, stud bolts that penetrate a container and connect the container and other members while maintaining airtightness with respect to the container having a pressure difference between the inside and the outside. The present invention belongs to the technical field of a mounting structure and a booster using the same.

  Conventionally, stud bolts are sometimes used when attaching containers to other members while keeping airtightness. For example, in a brake booster, a bolt shaft is passed through from the inside to the outside of each of the front shell and the rear shell, and each bolt is fixed to each shell by caulking, and the brake booster is attached by a bolt attached to the rear shell. Some of them are attached to the vehicle body, and the master cylinder is attached to the brake booster by bolts attached to the front shell.

Then, as shown in FIG. 21, a large number of convex portions 105 and concave portions 106 are formed around the bolt shaft portion 102 on the head end surface 103 of the bolt 101, and the bolt shaft portion 102 is drilled in the mounting plate 108. A portion of the bolt shaft portion 102 is plastically deformed from the other side surface through the provided through-hole 109 from the one side surface, and the bolt 101 is attached to the mounting plate 108 by the plastic deformation portion 107 and the head end surface 103. The convex portion 105 is inserted into the mounting plate 108 while being clamped and fixed, and the convex portion 105 is formed so as to protrude from the head end surface 103, and the height between the convex portions 105 is substantially the same as the head end surface 103. There is a structure in which a stopper portion 104 having a flat surface is provided and a concave portion 106 is formed between the convex portion 105 and the stopper portion 104 (see Patent Document 1).
Japanese Patent Publication No. 8-3327

  However, in the bolt shown in FIG. 21, the structure of the bolt 101 is complicated and difficult to manufacture, and the strength of the convex portion 105 is relatively weak and may be deformed. Further, during the caulking process, the bolt deforming portion 107 and the mounting plate 108 interfere with each other, and the bolt 101 may be inclined without being completely inserted.

  The present invention has been made in view of such circumstances, and an object thereof is to penetrate a container and connect the container and another member to a container having a pressure difference between the inside and the outside. Stud bolt mounting structure reduces variation in fastening strength, has high-precision airtightness, reduces defect rate, improves productivity, and cost-effective stud bolt mounting structure, and boost using the same Is to provide a device.

  In order to solve the above-described problem, a stud bolt mounting structure for connecting the container and another member through the container with respect to a container having a pressure difference between the inside and the outside is provided. A bolt head, a bolt shoulder having a diameter smaller than that of the bolt head, and a threaded portion having a diameter smaller than that of the bolt shoulder, the bolt shoulder having a protrusion and a groove on the outer periphery, The part has a knurl part that bites into the container at the time of caulking, and a bolt base whose diameter gradually increases from the knurl part side to the bolt head side between the knurl part and the bolt head part, The container includes a first member and a second member, and the first member and the second member are provided with a hole through which the stud bolt passes, and the diameter of the hole of the first member is the same as that of the knurled portion. Almost identical or slightly larger Made is, the diameter of the second member of the pores characterized in that it is substantially the same or slightly larger and the diameter of the bolt head side of the bolt base.

  Moreover, it has a space | gap between the hole of the said 2nd member, and the said bolt base part, The said 1st member is wound in the said space | gap at the time of the said crimping.

  Furthermore, the present invention is a booster using a stud bolt mounting structure, wherein the first member is a front shell of the booster, and the second member is a support plate.

  In the stud bolt mounting structure configured in this way, the gap between the stud bolt and the first member and the second member is substantially uniform on the circumference, eliminating the need for prior work such as welding for alignment, and improving productivity. Can be improved and low cost can be realized.

  In addition, by placing the stud bolt and the first member and the second member so that the gap between them is substantially uniform on the circumference, a substantially uniform force is applied on the circumference during caulking work, and a substantially uniform fastening force is obtained. It can be obtained, variation in fastening strength can be reduced, stable airtightness can be secured, defect rate is reduced, and productivity is improved. Moreover, since the 1st member is wound and fastened in the space | gap between the 2nd member and the volt | bolt base part of a stud bolt at the time of caulking work, fastening strength becomes large.

  Further, since the stud bolt mounting structure having high accuracy and airtightness is used for the booster, the performance of the booster is improved without much change in manufacturing process and cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a view showing a stud bolt according to an embodiment of the present invention. In the figure, 1 is a stud bolt, 2 is a bolt head, 2a is a stopper portion, 3 is a bolt shoulder portion, 3a is a bolt base portion, 3b is a knurled portion, 3c is a crimping portion, 4 is a bolt shaft portion, and 4a is a connecting portion. Reference numeral 4b denotes a screw portion, and 4c denotes an end portion.

  The stud bolt 1 is integrally formed with a bolt head 2 at one end, a bolt shoulder 3 at the middle, and a bolt shaft 4 at the other end. The bolt head 2 has a diameter d2 larger than that of the bolt shoulder 3 and the bolt shaft 4, and has a stopper portion 2a that serves as a stopper when mounted on the bolt shoulder 3 side.

The bolt shoulder portion 3 has a height h3, and has a tapered shape on the outer peripheral surface on the bolt head 2 side that gradually increases from the height h3 _a and the diameter d3 _b on the knurled portion side to the diameter d3 _a on the bolt head side. The bolt base 3a is formed in a similar manner, has a knurled portion 3b having a height h3 _b and a diameter d3 _b adjacent to the bolt base 3a, and a height h3 _c adjacent to the knurled portion 3b. The diameter d3 _b has a crimped portion 3c formed in a tapered shape or the like that gradually decreases so that the diameter on the bolt shaft portion side becomes the same as the diameter of the connecting portion 4a. Further, the diameter d3 _a and the diameter d3 _b are sizes between the bolt head 2 and the bolt shaft portion 4. The knurled portion 3b is formed with the protruding portions 3b ₁ and the groove portions 3b ₂ alternately arranged over the entire circumference, and it is particularly preferable that the number of the protruding portions 3b ₁ and the groove portions 3b ₂ is about 52. Note that the knurling portion 3b may be directly crimped without providing the crimping portion 3c.

  The bolt shaft portion 4 is coupled to the bolt shoulder portion 3 and includes a connecting portion 4a, a screw portion 4b, and an end portion 4c from the bolt shoulder portion 3 side. The diameter d4 of the screw portion 4b is smaller than the bolt head portion 2.

  FIGS. 2 to 8 are views showing a first embodiment of a process of caulking the stud bolt 1 having the structure of FIG. 1 to the container 10 including the first member 11 and the second member 12.

  FIG. 2 shows a state in which the container 10 is set on the second mold member 22.

The second mold member 22 has a recess 22a which is a cylindrical space having a depth slightly larger than the diameter d4 of the screw portion 4b formed on the bolt shaft portion 4 of the stud bolt 1 and longer than the height of the bolt shaft portion 4. It has a fixed second mold member 22 ₁ and a movable second mold member 22 _{2 on} the outside thereof. In the present embodiment, the upper surface of the movable second mold member 22 ₂ is formed in a convex shape, but may be a flat surface.

  Further, the first member 11 and the second member 12 are respectively provided with holes 11 a and 12 a through which the stud bolt 1 passes, and the hole 11 a of the first member 11 and the hole 12 a of the second member 12 are formed in the bolt shaft portion 4. It is formed larger than the diameter d4 of the threaded portion 4b.

  First, the first member 11 is set on the second mold member 22, and then the second member 12 is set on the first member 11. When the container 10 is set, it is not necessary to align the cores strictly, and the container 10 may be set so as to have an opening having a dimension of at least d4 into which the stud bolt 1 can be inserted. Moreover, there is no need for temporary fixing such as welding.

Next, the stud bolt 1 is set. FIG. 3 shows a state in the middle of setting the stud bolt 1. Since the diameter D22 of the recess 22a of the movable second mold member 22 ₂ of the second mold member 22 is larger than the diameter d4 of the screw portion 4b of the stud bolt 1, the screw portion 4b is dropped into the recess 22a from above and inserted.


FIG. 4 shows a state in which the stud bolt 1 is set, and FIG. 5 shows an enlarged view of a part of FIG. The stud bolt 1 stops dropping at a position where the stopper portion 2 a abuts against the second member 12. In this state, it is not necessary for the crimping portion 3 c and the second mold member 22 to contact each other, and it is preferable that the knurled portion 3 b is inserted into the hole 11 a of the first member 11.

  In addition, the 1st member 11 and the 2nd member 12 are still aligning because the crimping part 3c contact | abuts to the 1st member 11 or the 2nd member 12, or the bolt base part 3a contact | abuts to the 2nd member 12. There is no problem even if it is not.

Here, the hole 11a of the first member 11 has an inner diameter slightly larger D11 or substantially the same as the diameter d3 _b of the knurling portion 3b, the hole 12a of the second member 12, the diameter of the bolt head side of the bolt base portion 3a It has approximately the same or slightly larger inner diameter D12 and d3 _a. The height h3 of the bolt shoulder portion 3 is larger than the thickness H10 of the container 10, the height combined bolt base h3 _a and knurled portion h3 _b h3 _a + h3 _b also slightly larger than the plate thickness H10 of the container 10 It is preferable to set.

Next, as shown in FIG. 6, moves the first mold member 21 from above in the direction of the arrow to move the movable second mold member 22 ₂ from above in the direction of the arrow, the tip of the first mold part 21 21a is pressed against the bolt head 2 of the stud bolt 1 and caulked. Then, a part and staking portion 3c of the knurling portion 3b formed on the bolt shoulder portion 3 is crushed by the fixed second mold member 22 ₁ is spread to the outer periphery of the bolt shoulder portion 3.

  At this time, the caulking portion 3c is formed in a tapered shape or the like that gradually increases from the connecting portion 4a to the knurled portion 3b side, and the bolt base portion 3a gradually increases in diameter from the knurled portion 3b side to the bolt head 2 side. Even if the first member 11 or the second member 12 is in contact with the caulking portion 3c or the bolt base portion 3a in a state where the stud bolt 1 is set, the first mold member 21 is formed. The first member 11 or the second member 12 is automatically aligned along the surface of the caulking portion 3c, and the shaft center of the stud bolt 1, the hole 11a of the first member 11, and the second member 12 are pressed. The center of the hole 12a is caulked in a substantially coincident manner.

FIG. 7 is a diagram illustrating a state after crimping in which the stud bolt 1 and the container 10 are removed from the crimping jig 20 after the first mold member 21 is moved, and FIG. 8 is indicated by a dotted line in FIG. It is an enlarged view of a caulking part. In this state, the protruding piece 5 formed from a part of the knurled portion 3 b and the crimping portion 3 c bites into the first member 11, and the container 10 is sandwiched between the protruding piece 5 and the stopper portion 2 a of the bolt head 2. At this time, the remaining portion of the knurling portion 3b is press diameter than D11 of the hole 11a of the first member 11 by being crushed is increased, projections 3b ₁ of the knurling portion 3b bites into the first member 11, the stud The rotation of the bolt 1 is prevented. Further, the bolt base 3a is also crushed to increase the diameter.

  Further, the caulking portion 11b of the first member 11 is caught in the gap S between the second member 12 and the bolt base portion 3a of the stud bolt 1, and is clamped while being clamped between the stud bolt 1 and the second member 12. Is done.

  The bolt head 2 side of the stud bolt 1 corresponding to the inside of the container 10 and the end 4c side of the bolt shaft portion 4 of the stud bolt 1 corresponding to the outside of the container 10 are isolated, and the container 10 is sealed. Can keep the state.

As described above, since the stud bolt 1 and the first member 11 and the second member 12 are automatically aligned at the time of the caulking work, prior work such as welding for alignment is not necessary, and productivity is improved. Low cost can be realized. Further, since the gap S between the stud bolt 1 and the first member 11 and the second member 12 is caulked so as to be substantially uniform on the circumference, a substantially uniform force is applied on the circumference during the caulking work, and a substantially uniform fastening force. In addition, the variation in fastening strength can be reduced, stable airtightness can be ensured, the defect rate can be reduced, productivity can be improved, and low cost can be realized. Furthermore, since the fastening involving the first member 11 in the gap S ₁ between the second member 12 and the bolt base portion 3a of the stud bolt 1 during beforehand work, fastening strength is increased.

  Next, a second embodiment of the present invention will be described with reference to the drawings. The same reference numerals in the figure denote the same elements as those in the first embodiment.

  FIG. 9 thru | or FIG. 13 is a figure which shows 2nd Embodiment of the process of crimping the stud bolt 1 of the structure of FIG. 1 to the container 10 which consists of the 1st member 11, the 2nd member 12, etc. FIG.

  FIG. 9 shows a state where the container 10 is set on the second mold member 22.

  The second mold member 22 has a recess 22a which is a cylindrical space having a depth slightly larger than the diameter d4 of the screw portion 4b formed on the bolt shaft portion 4 of the stud bolt 1 and longer than the height of the bolt shaft portion 4. Have. In the present embodiment, the upper surface is formed in a convex shape, but it may be a flat surface.

  Further, the first member 11 and the second member 12 are respectively provided with holes 11 a and 12 a through which the stud bolt 1 passes, and the hole 11 a of the first member 11 and the hole 12 a of the second member 12 are formed in the bolt shaft portion 4. It is formed larger than the diameter d4 of the threaded portion 4b.

  First, the first member 11 is set on the second mold member 22, and then the second member 12 is set on the first member 11. When the container 10 is set, it is not necessary to align the cores strictly, and the container 10 may be set so as to have an opening having a dimension of at least d4 into which the stud bolt 1 can be inserted. Moreover, there is no need for temporary fixing such as welding.

  Next, the stud bolt 1 is set. FIG. 10 shows a state in the middle of setting the stud bolt 1. Since the diameter D22 of the recessed part 22a of the second mold member 22 is larger than the diameter d4 of the threaded part 4b of the stud bolt 1, the threaded part 4b is dropped into the recessed part 22a from above and inserted.

  FIG. 11 shows a state where the stud bolt 1 is set, and FIG. 12 shows an enlarged view of a part of FIG. The stud bolt 1 stops dropping at a position where the caulking portion 3 c contacts the second mold member 22. In this state, since the distance from the contact portion A between the crimping portion 3c and the second mold member 22 to the stopper portion 2a of the bolt head 2 is larger than the plate thickness H10 of the container 10, the stopper portion 2a is The first member 11 and the second member 12 are not aligned yet, and are not in contact with the member 12. In addition, there is no problem if the crimping portion 3c is in contact with the first member 11 or the second member 12 or the bolt base portion 3a is in contact with the second member 12, but the crimping portion 3c is in contact with the second mold member 22. The knurled portion 3b is inserted into the hole 11a of the first member 11, and the bolt base portion 3a is preferably not in contact with the stud bolt 1.

Here, the hole 11a of the first member 11 has an inner diameter slightly larger D11 or substantially the same as the diameter d3 _b of the knurling portion 3b, the hole 12a of the second member 12, the diameter of the bolt head side of the bolt base portion 3a It has approximately the same or slightly larger inner diameter D12 and d3 _a. The height h3 of the bolt shoulder portion 3 is larger than the thickness H10 of the container 10, the height combined bolt base h3 _a and knurled portion h3 _b h3 _a + h3 _b also slightly larger than the plate thickness H10 of the container 10 It is preferable to set.

  Next, as shown in FIG. 13, the first mold member 21 is moved in the direction of the arrow from above, and the tip 21 a of the first mold member 21 is pressed against the bolt head 2 of the stud bolt 1 and caulked. Then, a part of the knurled portion 3 b and the crimped portion 3 c formed on the bolt shoulder portion 3 are crushed by the second mold member 22 and are spread over the outer periphery of the bolt shoulder portion 3.

  At this time, the caulking portion 3c is formed in a tapered shape or the like that gradually increases from the connecting portion 4a to the knurled portion 3b side, and the bolt base portion 3a gradually increases in diameter from the knurled portion 3b side to the bolt head 2 side. Even if the first member 11 or the second member 12 is in contact with the caulking portion 3c or the bolt base portion 3a in a state where the stud bolt 1 is set, the first mold member 21 is formed. The first member 11 or the second member 12 is automatically aligned along the surface of the caulking portion 3c, and the shaft center of the stud bolt 1, the hole 11a of the first member 11, and the second member 12 are pressed. The center of the hole 12a is caulked in a substantially coincident manner. The state after caulking is the same as in the first embodiment.

As described above, since the stud bolt 1 and the first member 11 and the second member 12 are automatically aligned at the time of the caulking work, prior work such as welding for alignment is not necessary, and productivity is improved. Low cost can be realized. Further, since the gap S between the stud bolt 1 and the first member 11 and the second member 12 is caulked so as to be substantially uniform on the circumference, a substantially uniform force is applied on the circumference during the caulking work, and a substantially uniform fastening force. In addition, the variation in fastening strength can be reduced, stable airtightness can be ensured, the defect rate can be reduced, productivity can be improved, and low cost can be realized. Furthermore, since the fastening involving the first member 11 in the gap S ₁ between the second member 12 and the bolt base portion 3a of the stud bolt 1 during beforehand work, fastening strength is increased.

  Next, a third embodiment of the present invention will be described with reference to the drawings. The same reference numerals in the figure denote the same elements as those in the first embodiment.

  FIGS. 14 to 19 are views showing a third embodiment of the process of caulking the stud bolt 1 having the structure of FIG. 1 to the container 10 including the first member 11 and the second member 12. FIG. 14 shows a state in which the container 10 is set on the stud bolt 1, and FIG. 15 shows a partially enlarged view.

The caulking portion 10 a of the container 10 is a portion having a plate thickness H composed of the first member 11 and the second member 12. Caulked portion 11c of the first member 11 is a plate-shaped portion of the height h3 _b thinner than the plate thickness H11 of the knurling portion 3b, the diameter of the knurling portion 3b substantially equal to or slightly larger bolt head 2 than the diameter d3 _b of d2 A hole 11a having a smaller inner diameter D11 is formed. There is a chamfer B on the upper side of the hole 11a in FIG.

Crimping portion 12c of the second member 12 is a plate-shaped portion of the thick plate thickness than the height h3 _a of the bolt base portion 3a H12, about the same or slightly larger bolt head and the diameter d3 _a of the bolt head side of the bolt base portion 3a A hole 12a having an inner diameter D12 smaller than the diameter d2 of the portion 2 is formed.

First, as shown in FIG. 14, the 2nd member 12 is mounted in the stud bolt 1 set beforehand. At this time, the hole 12a of the second member 12 has a slightly larger inner diameter D12 or substantially the same as the diameter d3 _a of the bolt head side of the bolt base portion 3a, the bolt base portion 3a is subjected bolt head 2 side from the knurling portion 3b side Since the second member 12 is mounted from above the stud bolt 1, the second member 12 is automatically formed along the surface of the bolt base 3 a because the diameter is formed in a tapered shape or the like. The center is aligned, and the center of the stud bolt 1 and the center of the hole 12a of the second member 12 are substantially matched.

Further, the hole 11a of the first member 11 which has a diameter d3 _b substantially the same or slightly larger inner diameter D11 of the knurling portion 3b, staking portion 3c is gradually thicker a tapered shape, and the like toward the knurling portion 3b side from the connection portion 4a Therefore, when the first member 12 is placed from above the stud bolt 1, the first member 11 is automatically aligned along the surface of the caulking portion 3 c, and the axial center of the stud bolt 1 is formed. And the center of the hole 11b of the first member 11 substantially coincide. At this time, a gap S ₂ is formed between the stud bolt 1 and the first member 11 and the second member 12.

By placing in this way, the gap S ₂ between the stud bolt 1 and the first member 11 and the second member 12 becomes substantially uniform on the circumference, so that no prior work such as welding for alignment is required, and production And the cost can be reduced.

Since the total height h3 _a + h3 _b of the bolt base portion 3a and the knurled portion 3b is larger than the plate thickness H of the container 10, the crimped portion 3c of the bolt shoulder portion 3 penetrates the container 10 and protrudes. Become. The height h3 _a of the bolt base 3a of the bolt shoulder 3 is set to be smaller than the plate thickness D12 of the second member 12.

  As shown in FIG. 16, the container 10 in a state where the stud bolt 1 is inserted is set in the crimping jig 20 having the first mold member 21 and the second mold member 22. The first mold member 21 has a recess 21b corresponding to the shape of the bolt head 2 of the stud bolt 1, and when set, the bolt head 2 of the stud bolt 1 is fitted into the recess 21b. Place. The second mold member 22 has a cylindrical recess 22a having a depth slightly larger than the diameter d4 of the screw portion 4b formed on the bolt shaft portion 4 of the stud bolt 1 and longer than the height of the bolt shaft portion 4, When setting, it mounts so that the bolt axial part 4 of the stud bolt 1 may fit in this recessed part 22a.

  Next, as shown in FIG. 17, the second mold member 22 is moved in the direction of the arrow, and the tip of the second mold member 22 is pressed against the caulking portion 3 c formed on the bolt shoulder portion 3 of the stud bolt 1 to be caulked. . Then, a part of the knurled portion 3 b and the crimped portion 3 c formed on the bolt shoulder portion 3 are crushed by the second mold member 22 and are spread over the outer periphery of the bolt shoulder portion 3.

FIG. 18 is a view showing a state after caulking after the stud bolt 1 and the container 10 are removed from the caulking jig 20 after the second die member 22 is further moved in the direction of the arrow until it abuts against the first member 11. FIG. 19 is an enlarged view of a caulking portion indicated by a dotted line in FIG. In this state, the protruding piece 5 formed from a part of the knurled portion 3 b and the crimping portion 3 c bites into the first member 11, and the container 10 is sandwiched between the protruding piece 5 and the stopper portion 2 a of the bolt head 2. At this time, the remaining portion of the knurling portion 3b is press diameter than D11 of the hole 11b of the first member 11 by being crushed is increased, projections 3b ₁ of the knurling portion 3b bites into the first member 11, the stud The rotation of the bolt 1 is prevented. Further, the bolt base 3a is also crushed to increase the diameter.

Further, the caulking portion 11d of the first member 11 is caught in the gap S ₂ between the second member 12 and the bolt base portion 3a of the stud bolt 1, crimped while being held between the stud bolt 1 and the second member 12 It is concluded.

  The bolt head 2 side of the stud bolt 1 corresponding to the inside of the container 10 and the end 4c side of the bolt shaft portion 4 of the stud bolt 1 corresponding to the outside of the container 10 are isolated, and the container 10 is sealed. Can keep the state.

As described above, by placing the gap between the stud bolt 1 and the first member 11 and the second member 12 so as to be substantially uniform on the circumference, a substantially uniform force is applied on the circumference during the caulking work. A uniform fastening force can be obtained, variation in fastening strength can be reduced, stable airtightness can be secured, a defect rate is reduced, and productivity is improved. Moreover, since the fastening involving the first member 11 in the gap S ₂ between the second member 12 and the bolt base portion 3a of the stud bolt 1 during beforehand work, fastening strength is increased.

  FIG. 20 shows a state in which the stud bolt 1 is applied to a front shell 51 as an example of the first member of the present invention of the brake booster B. The brake booster B includes a shell 50 as an example of the container 10 of the present invention formed from a front shell 51 and a rear shell 53. A constant pressure chamber is defined on the front side of the shell 50 by a front shell 51 and a diaphragm (not shown). A negative pressure is introduced into the constant pressure chamber through a negative pressure introduction passage 54, and pressure (atmospheric pressure) is externally applied. It is sealed in a state where it is covered.

  The stud bolt 1 penetrates the bolt shoulder portion 3 and the bolt shaft portion 4 of the stud bolt 1 from the inside of the front shell 51 to the outside, and the master cylinder (not shown) is connected to the brake booster B by the screw portion 4b of the bolt shaft portion 4. It is trying to be attached to. At that time, a support plate 52 as an example of the second member of the present invention is placed on the caulking portion 51 a of the front shell 51.

  As described above, by applying the stud bolt 1 shown in FIG. 1 to the front shell 51 of the brake booster B, the constant pressure chamber on the front shell 51 side of the shell 50 and the outside are kept airtight with high accuracy. Is done.

It is a figure showing one embodiment of a stud bolt concerning the present invention. It is a figure which shows the state which set the container of 1st Embodiment. It is a figure which shows the state which has set the stud bolt of 1st Embodiment to the container. It is a figure which shows the state which set the stud bolt of 1st Embodiment to the container. It is the figure which expanded a part of FIG. It is a figure which shows the state which has crimped the stud bolt of 1st Embodiment. It is a figure which shows the state after crimping the stud bolt of 1st Embodiment. It is a figure which shows the state which set the container of 2nd Embodiment. It is a figure which shows the state which has set the stud bolt of 2nd Embodiment to the container. It is a figure which shows the state which set the stud bolt of 2nd Embodiment to the container. It is the figure which expanded a part of FIG. It is a figure which shows the state which has crimped the stud bolt of 2nd Embodiment. It is the figure which expanded a part of FIG. It is a figure which shows the state which set the stud bolt of 3rd Embodiment to the container. It is the figure which expanded a part of FIG. It is a figure which shows the state before crimping the stud bolt of 3rd Embodiment. It is a figure which shows the state which has crimped the stud bolt of 3rd Embodiment. It is a figure which shows the state after crimping the stud bolt of 3rd Embodiment. It is the figure which expanded a part of FIG. It is the figure which applied the stud bolt to the brake booster. It is a figure which shows the prior art.

Explanation of symbols

1 ... stud bolts, 2 ... bolt head, 2a ... stopper, 3 ... bolt shoulder portion, 3a ... bolt base portion, 3b ... knurling section, 3b ₁ ... projection, 3b ₂ ... groove, 3c ... caulking part, 4 ... Bolt shaft part, 4a ... connecting part, 4b ... screw part, 4c ... end part, 5 ... projecting piece, 10 ... container, 11 ... first member, 12 ... second member, 20 ... caulking jig, 21 ... first Mold member, 22 ... second mold member, B ... brake booster, 50 ... shell (container), 51 ... front shell (first member), 52 ... support plate (second member), 53 ... rear shell, 54 ... Negative pressure introduction passage

Claims (3)

  In a stud bolt for connecting the container and another member through the container with respect to a container having a pressure difference between the inside and the outside, the stud bolt includes a bolt head and a bolt head. A bolt shoulder portion having a small diameter, and a screw portion having a diameter smaller than that of the bolt shoulder portion, the bolt shoulder portion has a protrusion and a groove on the outer periphery, and at least a part of the knurled portion that bites into the container when caulking, Between the knurled portion and the bolt head portion, there is a bolt base portion whose diameter gradually increases from the knurled portion side toward the bolt head side, and the container has a first member and a second member. The first member and the second member have a hole through which the stud bolt penetrates, and the diameter of the hole of the first member is substantially the same as or slightly larger than the knurled portion. The hole diameter of the member is Stud bolt attachment structure, characterized in that it is substantially the same or slightly larger and the diameter of the bolt head side of the belt base.   2. The stud bolt mounting structure according to claim 1, wherein a gap is provided between the hole of the second member and the bolt base portion, and the first member is caught in the gap during the caulking.   The booster using a stud bolt mounting structure according to claim 1 or 2, wherein the first member is a front shell of a booster, and the second member is a support plate. .

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