JP6649125B2 - How to fix tandem type negative pressure booster and sleeve to partition plate - Google Patents

Description

  According to the present invention, the inside of a booster shell formed by combining a front shell half and a rear shell half is divided into a front shell chamber and a rear shell chamber by a partition plate connected to the booster shell, At the rear surface of a front booster piston housed in the chamber so as to be able to reciprocate back and forth, an outer peripheral edge is formed on the booster shell while dividing the front shell chamber into a front front negative pressure chamber and a rear front working chamber. A rear diaphragm is attached to the rear shell chamber. The rear booster piston is accommodated in the rear shell chamber so as to reciprocate back and forth. A rear diaphragm whose outer peripheral edge is supported by the booster shell while being partitioned is fixed to the partition plate and inserted through a cylindrical sleeve that air-tightly penetrates the rear diaphragm. A tandem negative pressure booster in which an i-rod is airtightly penetrated through the front booster piston and the front diaphragm and fixed between the front shell half and the rear shell half, and fixing the sleeve to the partition plate About the method.

  Such a tandem-type negative pressure booster is already known, for example, from Patent Document 1.

JP 2004-58959 A

  In the structure disclosed in Patent Document 1, the sleeve is press-fitted and fixed to the partition plate, and in such a fixing structure, it is necessary to increase the dimensional accuracy of the press-fitted portion, which causes a cost increase.

  The present invention has been made in view of the above circumstances, and provides a method of fixing a tandem type negative pressure booster and a sleeve to a partition plate, which facilitates management of dimensional accuracy and can reduce costs. Aim.

  In order to achieve the above object, the present invention provides a booster shell having a front shell half and a rear shell half joined to each other, wherein a partition plate connected to the booster shell forms a front shell chamber and a rear shell chamber. The front shell chamber is divided into a front front negative pressure chamber and a rear front working chamber at a rear surface of a front booster piston housed in the front shell chamber so as to be able to reciprocate back and forth. A front diaphragm, whose outer peripheral edge is supported by the booster shell, is connected to the rear surface of a rear booster piston which is reciprocally movable in the rear shell chamber. A rear diaphragm whose outer peripheral edge is supported by the booster shell is bound to the booster shell while being partitioned into a chamber and a rear working chamber on the rear side. The rear diaphragm is fixed to the partition plate and passes through the rear diaphragm in an airtight manner. In a tandem type negative pressure booster, a tie rod inserted through a sleeve is airtightly penetrated through the front booster piston and the front diaphragm and fixed between the front shell half and the rear shell half. An annular locking flange projecting inward in the radial direction is integrally provided at one end of the sleeve on the partition plate side so as to form a central hole coaxial with the sleeve, and the one end of the sleeve is provided. A support cylinder portion inserted into the center hole is integrally provided with the partition plate abutting on the annular seal member via an annular seal member, and a distal end portion of the support cylinder portion is engaged with the locking flange portion This is a first feature.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the sleeve is made of resin.

  According to the present invention, in addition to the configuration of the first or second aspect, an annular seal portion that comes into sliding contact with the outer circumference of the tie rod on the front diaphragm closer to the front working chamber than the front booster piston is provided. Are integrally formed as a third feature.

  Furthermore, the present invention provides a method for fixing a sleeve to a partition plate for fixing the sleeve to the partition plate at the time of manufacturing the tandem type negative pressure booster having the first to third features, wherein the center is provided over the entire axial length. The support tubular portion having an outer diameter smaller than the inner diameter of the hole is provided integrally with the partition plate, and the locking flange portion is provided integrally with one end of the sleeve, and the support flange is provided integrally with the one end of the sleeve. Setting the partition plate in a state where the sealing member is sandwiched and the support tubular portion is inserted through the center hole on a receiving jig; and inserting a pressing jig from the other end side into the sleeve to support the partition plate. The fourth feature is that the step of sequentially expanding the diameter of the tip portion of the cylindrical portion is performed.

  Note that the third seal member 55 of the embodiment corresponds to the seal member of the present invention.

  According to the first feature of the present invention, one end of the sleeve is in contact with the partition plate via the annular seal member, and the support tubular portion provided integrally with the partition plate is a locking flange portion at one end of the sleeve. Is inserted into the center hole formed by the above, and the front end of the support cylindrical portion is engaged with the locking flange, so that one end of the sleeve is separated from the partition by a sealing member. And since the locking flange portion is sandwiched between the distal ends of the support cylinder portions, the fixing flange portion is fixed to the partition plate, so that dimensional accuracy can be easily controlled and cost reduction can be achieved as compared with fixing by press fitting. It becomes possible.

  Further, according to the second feature of the present invention, it is possible to reduce the weight and cost by forming the sleeve from resin.

  According to the third aspect of the present invention, since the seal portion formed integrally with the front diaphragm is closer to the outer circumference of the tie rod on the front working chamber side than the front booster piston, the front negative pressure chamber In order to secure the effective stroke of the front diaphragm and seal to the side where the volume is reduced, the distance between the front booster piston and the front shell half in the inactive state along the axis of the tie rod should be minimized. Therefore, the total length of the tandem-type negative pressure booster in the direction along the axis of the tie rod can be shortened, and the mountability to a vehicle can be improved.

  Further, according to the fourth feature of the present invention, when the sleeve is fixed to the partition plate, the seal member is sandwiched between the sleeve and one end of the sleeve, and the support cylinder is inserted into the center hole of the locking flange. The process of setting the partition plate on the receiving jig and the process of inserting the pressing jig into the sleeve from the other end and enlarging the tip of the supporting cylindrical portion in order to sequentially execute the steps, The distal end can be engaged with the locking flange, and the work of fixing the sleeve to the partition plate becomes easy.

It is a longitudinal section of a tandem type negative pressure booster. FIG. 2 is an enlarged view of a portion indicated by an arrow 2 in FIG. 1. It is a figure which shows the fixing operation procedure of a sleeve to a partition board.

  Hereinafter, an embodiment of the present invention will be described with reference to the attached FIGS. 1 to 3. First, in FIG. 1, the front surface of the booster shell 5 of the tandem type negative pressure booster B is Is mounted on the cylinder body 6 of the brake master cylinder M which is amplified and driven.

  The booster shell 5 comprises a front shell half 7 and a rear shell half 8 mutually connected. A rear end of the front shell half 7 is formed so as to surround a front end of the rear shell half 8, and a first cylindrical member fixed to a front outer periphery of the rear shell half 8. The outer periphery of the annular plate portion 9a provided in the front shell half 7 closes the annular space created between the rear end of the front shell half 7 and the front end of the rear shell half 8 from behind. Joined to the back end.

  The inside of the booster shell 5 is partitioned into a front shell chamber 12 and a rear shell chamber 13 by a partition plate 10 connected to the booster shell 5. A front end of a second cylindrical member 11 is fixed to the outer periphery of the partition plate 10, and a rear end of the second cylindrical member 11 is connected to a rear end of the front shell half 7. Thereby, the partition plate 10 is connected to the booster shell 5.

  A front booster piston 14 is accommodated in the front shell chamber 12 so as to be able to reciprocate back and forth. On the rear surface of the front booster piston 14, a front negative pressure chamber is provided in the front shell chamber 12. A front diaphragm 15 partitioned into a front working chamber 16 and a rear front working chamber 17 is attached. The front diaphragm 15 has an annular first outer bead portion 15 a at the outer peripheral edge thereof, and is provided between the outer periphery of the front end of the second tubular member 11 and the front shell half 7. The front diaphragm 15 is supported by the booster shell 5 by sandwiching the first outer peripheral bead portion 15a. The front negative pressure chamber 16 is connected to a negative pressure source V (for example, inside an intake manifold of an internal combustion engine) via a negative pressure introducing pipe 4 connected to the front shell half 7.

  A rear booster piston 18 is accommodated in the rear shell chamber 13 so as to be able to reciprocate back and forth. A rear diaphragm 19 partitioned into a rear working chamber 21 is attached. The rear diaphragm 19 has an annular second outer bead portion 19a at its outer peripheral edge, and is provided between the outer periphery of the first tubular member 9 and the inner periphery of the rear end of the second tubular member 11. The rear diaphragm 19 is supported by the booster shell 5 by the second outer peripheral bead portion 19a being sandwiched between the rear diaphragm beads 19a.

  The front booster piston 14 and the front diaphragm 15 have a cylindrical shape which is slidably supported by the partition plate 10 with an annular first seal member 22 interposed between the front booster piston 14 and the partition plate 10. The rear booster piston 18 and the rear diaphragm 19 are connected to the outer periphery of the rear end of the boss 23.

  A front end of a rear extension cylinder 8a extending rearward is coaxially and integrally connected to a center portion of a rear wall of the rear shell half 8, and a second sealing member annular to the rear extension cylinder 8a. A front end portion of the valve cylinder portion 24 slidably supported via 26 constitutes a piston boss 25 together with the boss portion 23 and is coaxially and integrally connected to a rear end portion of the boss portion 23. The piston boss 25 is formed of a synthetic resin.

  In the valve cylinder portion 24, a valve piston 27, an input rod 28 connected to the valve piston 27, and front and rear working chambers 17, 21 in accordance with the forward and backward movements of the input rod 28 are provided. A control valve 29 for switching communication between the rear negative pressure chambers 16 and 20 and the atmosphere is provided, and a brake pedal P is connected to a rear end of the input rod 28.

  The valve piston 27 is slidably fitted in a guide hole 30 provided in the valve cylinder 24. At the rear end of the valve piston 27, a flange-shaped air introduction valve seat 31 projecting outward in the radial direction is integrally formed. An annular negative pressure introducing valve seat 32 is formed in the valve cylinder portion 24 and is arranged concentrically around the air introducing valve seat 31.

  The valve piston 27 is provided with a connection concave portion 33 that is opened at the center of the rear end surface of the air introduction valve seat 31. A ball joint 28a formed at the front end of the input rod 28 is fitted into the connection recess 33, and a part of the valve piston 27 is caulked so as to engage with the ball joint 28a. Is swingably connected to the valve piston 27.

  An expandable and contractible cylindrical valve body 34 having an annular valve portion 34 a is attached to the valve cylinder portion 24 by a valve holder 35. The valve body 34 is formed of an elastic material such as rubber, and an annular reinforcing plate 36 is embedded in the valve portion 34a.

  The valve portion 34a is disposed so as to be able to be seated on the atmosphere introduction valve seat 31 and the negative pressure introduction valve seat 32. A valve spring between the reinforcing plate 36 of the valve portion 34a and the input rod 28 for urging the valve portion 34a to the side for seating the air introduction valve seat 31 and the negative pressure introduction valve seat 32. The control valve 29 includes the air introduction valve seat 31, the negative pressure introduction valve seat 32, the valve body 34, and the valve spring 37.

  An input return spring 38 is contracted between the valve holder 35 and the input rod 28, and the input rod 28 is urged in a retreating direction by a spring force exerted by the input return spring 38, and the valve holder 35 35 is held at a fixed position in the valve barrel 24.

  A front annular chamber 39 surrounding the negative pressure introducing valve seat 32 is formed in the valve cylinder 24, and the front surface of the valve portion 34a faces the front annular chamber 39. The outer periphery of the valve portion 34a is slidably in close contact with the inner peripheral surface of the valve cylinder portion 24 behind the front annular chamber 39. Therefore, the front annular chamber 39 is closed when the valve portion 34a is seated on the negative pressure introduction valve seat 32. Further, a rear annular chamber 40 separated from the front annular chamber 39 is defined between the valve body 34 and the valve cylinder 24 so as to face the rear surface of the valve section 34a.

  The front annular chamber 39 communicates with the front negative pressure chamber 16 through the first passage 41 formed in the valve cylinder 24 and the inside of the boss 23, and branches off from the first passage 41 to form the front annular chamber 39. It communicates with the rear negative pressure chamber 20 via a second passage 42 provided in the valve cylinder 24. Further, the valve cylinder portion 24 has a third passage 43 formed so as to allow one end to pass through the rear working chamber 21 and to open the other end between the negative pressure introduction valve seat 32 and the atmosphere introduction valve seat 31. Provided.

  At a plurality of locations around the piston boss 25, a front end of a cylindrical sleeve 45 extending in parallel with the piston boss 25 is fixed to the partition plate 10, and the sleeve 45 hermetically seals the rear diaphragm 19. The front working chamber 17 and the rear working chamber 21 communicate with each other via the sleeve 45.

  The valve barrel portion 24 is covered with an extendable boot 46 having a front end coupled to the rear extension cylinder 8a. A rear end of the boot 46 is attached to the input rod 28, and the rear end of the boot 46 is At the end, an air inlet 47 communicating with the inside of the valve body 34 is provided.

  Further, a key 48 extending along the diameter line of the valve cylinder 24 at the axially intermediate portion of the guide hole 30 is attached to the valve cylinder 24 so as to define the retreat limit of the valve piston 27. Can be

  A circular concave portion 49 having a diameter larger than that of the guide hole 30 and being coaxial with the guide hole 30 is formed at the front end of the valve cylinder portion 24, and the front end of the valve piston 27 is brought into contact with the concave portion 49. An elastic body 50 such as rubber, which is formed in a disk shape so as to be obtained, is fitted into the recess 49. On the other hand, the rear end of the output rod 52 whose front end is connected to the piston rod 51 of the brake master cylinder M is inserted into the recess 49 with the elastic body 50 interposed between the output rod 52 and the valve cylinder 24. Is done. A coil-shaped valve barrel return spring 53 is contracted between the valve barrel 24 and the front shell half 7.

  Incidentally, at the rear end of the cylinder body 6 of the brake master cylinder M, a flange portion 6a and a cylindrical protrusion 6b projecting rearward from the flange portion 6a are integrally provided. At the center of the shell half 7, a short cylindrical portion 7 a having a bottom and forming an insertion hole 54 into which the cylindrical projection 6 b is inserted is inserted into the front negative pressure chamber 16. The front end portion of the valve barrel return spring 53 is in contact with the front shell half 7 so as to surround the base of the short cylindrical portion 7a.

  A tie rod 56 that is airtightly penetrated through the front booster piston 14 and the front diaphragm 15 and fixed between the front shell half 7 and the rear shell 8 is inserted through the sleeve 45.

  The tie rod 56 has a male thread 57 at its front end and a male thread 58 at its rear end and penetrates the front shell half 7 and the rear shell half 8. An annular stopper plate 59 is sandwiched between an annular projection 56a integrally provided near the front portion of the 56 and the front shell half 7, and a flange portion 56b integrally provided near the rear portion of the tie rod 56 is provided. The tie rod 56 is fixed between the front shell half 7 and the rear shell half 8 by being caulked to the rear shell half 8.

  The male thread portion 57 at the front end of the tie rod 56 is inserted into the flange portion 6a of the cylinder body 6, and a nut 61 having a washer 60 interposed between the flange portion 6a and the nut 61 is screwed into the male thread portion 57. Thus, the cylinder body 6 is attached to the front shell half 7, that is, the booster shell 5.

  The male screw portion 58 at the rear end of the tie rod 56 is inserted into a support portion S such as a vehicle body, and a nut 63 having a washer 62 interposed between the male screw portion 58 and the support portion S is screwed into the male screw portion 58. Thus, the rear shell half 8, that is, the booster shell 5 is attached to the support portion S.

  In the rest state of the tandem type negative pressure booster B, the front and rear booster pistons 14 and 18 and the input rod 28 are located at the respective retreat limits, and the rear end of the valve piston 27 is introduced into the atmosphere. While seating on the valve portion 34a of the valve body 34, the valve seat 31 presses the valve portion 34a to slightly separate from the negative pressure introducing valve seat 32. As a result, the negative pressure in the front and rear negative pressure chambers 16 and 20 is transmitted to the front and rear working chambers 17 and 21, and both chambers 16, 20: 17 and 21 have the same pressure. The pistons 14 and 18 and the valve barrel 24 are held at the retracted positions by the urging force of the valve barrel return spring 53.

  When the brake pedal P is depressed to brake the vehicle and the input rod 28 and the valve piston 27 are advanced, the valve cylinder portion 24 advances with the valve piston 27 held at the retracted position. Therefore, the urging force of the valve spring 37 causes the valve body 34 to extend so that the valve portion 34a is seated on the negative pressure introduction valve seat 32. At the same time, the atmosphere introduction valve seat 31 is separated from the valve body 34, The air flowing into the valve cylinder 24 from the air inlet 47 passes through the air inlet valve seat 31 and is introduced into the front and rear working chambers 17 and 21, and the front and rear working chambers 17 and 21 are moved to the front. Since the pressure is higher than that of the rear negative pressure chambers 16 and 20, the front and rear booster pistons 14 and 18 obtain forward thrust based on the pressure difference between them, so that the valve cylinder 24, the valve piston 27 and the output rod 52 are connected. With this movement, the piston moves forward against the force of the valve cylinder return spring 53, and the piston rod 51 of the brake master cylinder M is pressed forward by the output rod 52.

  Referring also to FIG. 2, the sleeve 45 is made of resin, and at one end of the sleeve 45 on the partition plate 10 side, an annular locking flange 65 projecting inward in the radial direction is provided. 45 are provided integrally with each other so as to form a center hole 66 coaxial therewith.

  On the other hand, a tapered surface 67 is formed on the surface of the locking flange 65 facing the partition plate 10, and the one end of the sleeve 45 is a third surface interposed between the tapered surface 67 and the partition plate 10. The partition plate 10 is in contact with the partition plate 10 via a seal member 55 (a seal member in the present invention), and the partition plate 10 is integrally provided with a support cylindrical portion 68 inserted into the center hole 66. The sleeve 45 is fixed to the partition plate 10 by the distal end portion 68a of the support tubular portion 68 being engaged with the locking flange 65.

  In this embodiment, the outer diameter D1 of the distal end 68a is larger than the inner diameter D2 of the center hole 66 in order to engage the distal end 68a of the support cylinder 68 with the locking flange 65. The distal end 68 a of the support cylinder 68 is engaged with the support flange 65 by this.

  In fixing the sleeve 45 to the partition plate 10, the support cylinder portion 68 having an outer diameter D3 smaller than the inner diameter D2 of the center hole 66 over the entire length in the axial direction is provided integrally with the partition plate 10 and the sleeve 45 The locking flange 65 is integrally provided at one end of the sleeve 45, and as shown in FIG. 3A, a third seal member 55 is sandwiched between the one end of the sleeve 45 and the support A step of setting the partition plate 10 with the cylindrical portion 68 inserted through the center hole 66 on a receiving jig 69 and, as shown in FIG. 3B, a tapered pressing surface 70 a at a distal end portion. The pushing jig 70 is inserted into the sleeve 45 from the other end side so that the outer diameter D1 of the distal end 68a of the support cylinder 68 is larger than the inner diameter D2 of the center hole 66. To Bari Sequentially performing a step of diameter machining grayed.

  The front diaphragm 15 is integrally formed with an annular seal portion 72 that comes into sliding contact with the outer periphery of the tie rod 56 in an airtight manner. The seal portion 72 is more integral with the front working chamber 17 than the front booster piston 14. The tie rod 56 is formed so as to be in airtight sliding contact with the outer periphery of the tie rod 56.

  In this embodiment, the sealing portion 72 integrally includes two annular projecting portions 72a and 72b projecting inward in the radial direction so as to be in airtight sliding contact with the outer periphery of the tie rod 56 and spaced apart in the axial direction. The tie rod 56 is formed in a cylindrical shape, and has a cylindrical extension portion 72c whose tip end is slidably contacted with the outer periphery of the tie rod 56 in an airtight manner while being partially inserted into the sleeve 45. The front ends of the annular projecting portions 72a and 72b and the extending portion 72c are in airtight sliding contact with the outer periphery of the tie rod 56 on the front working chamber 17 side of the front booster piston 14. .

  Next, the operation of this embodiment will be described. An annular locking flange 65 extending inward in the radial direction forms a central hole 66 coaxial with the sleeve 45 at one end of the sleeve 45 on the partition plate 10 side. A support cylinder 68 inserted into the center hole 66 is provided on the partition plate 10 provided integrally with the partition 45 and in contact with the one end of the sleeve 45 via a third seal member 55 which is annular. Since the distal end portion 68a of the support tubular portion 68 is engaged with the locking flange 65, one end of the sleeve 45 has the third seal member 55 interposed between the partition 45 and the partition plate 10. In this state, the locking flange 65 is sandwiched between the partition plate 10 and the distal end portion 68a of the support tube portion 68, so that the locking flange 65 is fixed to the partition plate 10, and the dimensional accuracy is controlled as compared with the fixing by press fitting. Is easy and costs are reduced. Theft is possible.

  Moreover, since the sleeve 45 is made of resin, it is possible to reduce the weight and cost.

  When the sleeve 45 is fixed to the partition plate 10, the support tubular portion 68 having an outer diameter D3 smaller than the inner diameter D2 of the center hole 66 over the entire length in the axial direction is provided integrally with the partition plate 10, and The locking flange 65 is integrally provided at one end of the sleeve 45, and the third sealing member 55 is interposed between the locking flange 65 and the one end of the sleeve 45. A step of setting the inserted partition wall plate 10 on a receiving jig 69, and inserting a pressing jig 70 into the sleeve 45 from the other end side to expand the diameter of the distal end portion 68a of the support cylindrical portion 68. Since the steps are sequentially performed, the distal end portion 68a of the support tube portion 68 can be expanded in diameter and can be engaged with the locking flange 65, so that the operation of fixing the sleeve 45 to the partition plate 10 becomes easy.

  Further, the front diaphragm 15 is integrally formed with an annular seal portion 72 that is in air-tight sliding contact with the outer periphery of the tie rod 56 on the front working chamber 17 side of the front booster piston 14. In securing the effective stroke of the front diaphragm 15 and the seal portion 64 to the side of reducing the volume, the direction along the axis of the tie rod 56 between the front booster piston 14 and the front shell half 7 in the non-operating state. Can be shortened as much as possible, and the total length of the tandem type negative pressure booster B in the direction along the axis of the tie rod 56 can be shortened, so that the mountability to the vehicle can be improved.

  In addition, since the sealing portion 72 is integrally formed with an extended portion 72c which is supported by the partition plate 10 and partially inserted into a cylindrical sleeve 45 which passes through the rear diaphragm 19 in a gas-tight manner, The contact position of the seal portion 72 with the tie rod 56 can be arranged more rearward, and the total length of the tandem-type negative pressure booster B in the direction along the axis of the tie rod 56 can be further reduced. The mountability can be further improved.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, in the above-described embodiment, the distal end portion 68a of the support cylindrical portion 68 is enlarged in diameter to engage with the locking flange portion 65. However, the distal end portion 68a is caulked to engage with the locking flange portion 65. You may make it match.

5 Booster shell 7 Front shell half 8 Rear shell half 10 Partition plate 12 Front shell chamber 13 Rear shell chamber 14 Front Booster piston 15 Front diaphragm 16 Front negative pressure chamber 17 Front working chamber 18 Rear booster piston 19 Rear diaphragm 20 Rear negative pressure chamber 21 -Rear working chamber 45-Sleeve 55-Seal member 56-Tie rod 65-Locking flange 66-Center hole 68-Support cylinder 68a-Tip of the support cylinder Part 69: Receiving jig 70: Pushing jig 72: Seal part B: Tandem type negative pressure booster

Claims (4)

  The inside of the booster shell (5) formed by connecting the front shell half (7) and the rear shell half (8) is separated by a partition plate (10) connected to the booster shell (5). 12) and a rear shell chamber (13). The front shell chamber (12) has a rear face of a front booster piston (14) housed in the front shell chamber (12) so as to be able to reciprocate back and forth. A front diaphragm (15) whose outer peripheral edge is supported by the booster shell (5) is joined to the booster shell (5) while partitioning the front diaphragm into a front front negative pressure chamber (16) and a rear front working chamber (17). The rear shell chamber (13) has a front rear negative pressure chamber (20) and a rear rear section on a rear surface of a rear booster piston (18) housed in the rear shell chamber (13) so as to reciprocate back and forth. While partitioning the working chamber (21), the booster shell ( ), A rear diaphragm (19) whose outer peripheral edge is supported is attached thereto, and is fixed to the partition plate (10) and inserted through a cylindrical sleeve (45) that hermetically penetrates the rear diaphragm (19). A tie rod (56) tightly penetrates through the front booster piston (14) and the front diaphragm (15) and is fixed between the front shell half (7) and the rear shell half (8). In the tandem type negative pressure booster, an annular locking flange (65) projecting inward in the radial direction is provided at one end of the sleeve (45) on the side of the partition plate (10). The partition plate (10), which is integrally provided so as to form a coaxial center hole (66) and abuts on the one end of the sleeve (45) via an annular seal member (55), has the center. Hole (66) A tandem type negative tube, wherein a support tube portion (68) to be inserted is provided integrally, and a tip portion (68a) of the support tube portion (68) is engaged with the locking flange (65). Pressure booster.   The tandem type negative pressure booster according to claim 1, wherein the sleeve (45) is made of resin.   The front diaphragm (15) is integrally provided with an annular seal portion (72) that comes into sliding contact with the outer periphery of the tie rod (56) on the front working chamber (17) side with respect to the front booster piston (14). The tandem type negative pressure booster according to claim 1 or 2, wherein the tandem type negative pressure booster is formed.   A method of fixing a sleeve to a partition plate for fixing the sleeve (45) to the partition plate (10) at the time of manufacturing the tandem-type negative pressure booster according to any one of claims 1 to 3, The support cylinder (68) having an outer diameter (D3) smaller than the inner diameter (D3) of the center hole (66) over the entire length in the axial direction is provided integrally with the partition plate (10) and the sleeve (45) The locking flange (65) is integrally provided at one end, and the sealing member (55) is sandwiched between the locking flange (65) and the one end of the sleeve (45). A step of setting the partition plate (10) inserted through the hole (66) on a receiving jig (69), and inserting a pressing jig (70) into the sleeve (45) from the other end side. Tip part (68a) of support cylinder part (68) Method of fixing the partition plate of the sleeve and executes a step of diameter machining sequence.

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