Pressure booster

Abstract

A pressure booster (10) comprises: an inlet port (12) into which compressed air flows; drive chambers (32, 42) that drive a first piston (24) by means of the compressed air; a second piston (26) that is coupled to the first piston (24); pressure boosting chambers (34, 44) in which compression of the compressed air is performed by the second piston (26); an outlet port (14) that causes the compressed air having undergone compression in the pressure boosting chamber (44) to flow out; an exhaust part (16) through which the compressed air in the drive chamber (32) is discharged; and a selector valve (30) that connects the drive chamber (32) to the inlet port (12) or to the exhaust part (16) by switching therebetween. A common drive flow path (60) for connecting the inlet port (12) to the drive chamber (32) has a throttle part (62) that regulates the flow rate of the compressed air flowing toward the drive chamber (32) and that does not hinder the discharge of the compressed air from the drive chamber (32).

Description

Pressure booster

[0001] The present disclosure relates to a pressure booster device that boosts the pressure of compressed air.

[0002] In compressed air piping systems (compressed air supply systems) in factories and other facilities, there are some locations that require high-pressure compressed air. In these locations, a pressure booster is used.

[0003] In a pressure intensifier, a pressure intensifier piston, which further compresses the compressed air, is driven by a drive piston driven by compressed air. For example, Japanese Utility Model Laid-Open Publication No. 60-116084 describes a pressure intensifier having a pair of cylinders sandwiching a partition wall, with the pistons of each cylinder connected by a piston rod. This pressure intensifier intensifies the pressure of the compressed air by alternately switching one piston and the other piston between a drive piston and a pressure intensifier piston depending on the stroke direction.

[0004] When the flow rate of the boosted compressed air (boosted air) approaches its nominal maximum value, the pressure of the boosted air drops, and the pressure at the outlet port approaches the pressure of the compressed air at the inlet port. Under these operating conditions, only a portion of the compressed air (drive air) supplied for driving contributes to the operation of the drive piston, resulting in wasted drive air.

[0005] Therefore, there is a need for a booster device that can suppress the inflow of excess drive air without causing a decrease in operating speed under operating conditions where a large flow rate of boosted air is output.

[0006] An object of the present invention is to solve the above-mentioned problems.

[0007] A first aspect of the present disclosure is a pressure booster device comprising: an inlet port through which compressed air flows in; a drive chamber that drives a first piston with the compressed air flowing in from the inlet port; a second piston connected to the first piston; a pressure booster chamber in which the compressed air is compressed by the second piston; an outlet port through which the compressed air compressed in the pressure booster chamber flows out; an exhaust section that exhausts the compressed air from the drive chamber; and a selector valve that selects and connects the inlet port or the exhaust section to the drive chamber, wherein a flow path connecting the inlet port and the drive chamber has a throttle section that restricts a flow rate of the compressed air toward the drive chamber and does not hinder the discharge of the compressed air from the drive chamber.

[0008] The booster device of the above aspect can suppress waste of drive air without causing a decrease in operating speed under operating conditions in which boosted air is output at a large flow rate.

[0009] FIG. 1 is an explanatory diagram of a pressure intensifier according to a first embodiment. FIG. 2 is a perspective view of the pressure intensifier of FIG. 1. FIG. 3 is an exploded perspective view of the switching valve and flow path member of FIG. 2. FIG. 4 is an enlarged partial cross-sectional view of the flow path member taken along line IV-IV of FIG. 3. FIG. 5 is an explanatory diagram of the operation of the pressure intensifier of FIG. 1 during the second stroke. FIG. 6A is a graph showing the piston position of the pressure intensifier of FIG. 1 and the pressure changes in the first and second drive chambers. FIG. 6B is a graph showing the pressure changes in the first drive chamber in the first embodiment and the pressure changes in the first drive chamber in a comparative example, superimposed on each other. FIG. 7A is an explanatory diagram of an air circuit of a pressure intensifier according to a second embodiment, and FIG. 7B is a cross-sectional view of the pressure intensifier of FIG. 7A. FIG. 8 is an explanatory diagram of an air circuit of a pressure intensifier according to a third embodiment. FIG. 9 is a longitudinal cross-sectional view of the pressure intensifier of FIG. 8. FIG. 10 is an enlarged cross-sectional view of the throttle with check valve of FIG. 9. FIG. 11 is an explanatory diagram of a pressure intensifier according to a fourth embodiment. 12A is a perspective view of the appearance of the pressure intensifier of FIG. 11, and FIG. 12B is a cross-sectional view taken along line XIIB-XIIB of FIG. 12A.

[0010] (First embodiment) The pressure intensifier 10 shown in Fig. 1 drives a piston using a portion of the supply air (compressed air) introduced through an inlet port 12, compresses and intensifies the supply air, and outputs the compressed air from an outlet port 14. The portion of the supply air introduced through the inlet port 12 is used to drive the piston. The compressed air used to drive the piston is discharged through an exhaust section 16. Because the pressure intensifier 10 is driven by the supply air, it is suitable for use in locations without a power source. The pressure intensifier 10 can also be used to supply compressed air to locations requiring local pressure increase in a compressed air supply system in a factory, for example.

[0011] The pressure booster 10 includes a first cylinder 18, a second cylinder 20, a partition 22, a first piston 24, a second piston 26, a piston rod 28, a switching valve 30, a first pilot valve 56, and a second pilot valve 58. The first cylinder 18, the second cylinder 20, and the partition 22 are connected to each other in the axial direction. The first cylinder 18 is connected to a first-direction end 22a of the partition 22, and the second cylinder 20 is connected to a second-direction end 22b of the partition 22 opposite the first-direction end 22a. In the axial direction, the direction from the partition 22 toward the first cylinder 18 is referred to as the first direction, and the direction from the partition 22 toward the second cylinder 20 is referred to as the second direction.

[0012] The first cylinder 18 has a first cylinder chamber 18a extending in the axial direction. A first piston 24 is housed in the first cylinder chamber 18a. The first piston 24 slides axially inside the first cylinder chamber 18a while airtightly dividing the first cylinder chamber 18a into a first drive chamber 32 and a first pressure booster chamber 34. The first drive chamber 32 is located on a first side of the first piston 24, and the first pressure booster chamber 34 is located on a second side of the first piston 24.

[0013] The first drive chamber 32 communicates with a first drive flow path 36. The first drive flow path 36 supplies and discharges compressed air (drive air) to and from the first drive chamber 32 to drive the first piston 24. The first drive flow path 36 opens near the end of the first cylinder chamber 18a in the first direction.

[0014] The first booster chamber 34 communicates with a first supply flow path 38 and a first booster flow path 40. The first supply flow path 38 introduces compressed air (supply air) to be boosted into the first booster chamber 34. The first supply flow path 38 communicates with the inlet port 12 via the booster chamber supply flow path 13. A check valve 38a is provided in the first supply flow path 38. The check valve 38a allows supply air to pass only in the direction toward the first booster chamber 34.

[0015] The first pressure increase passage 40 discharges compressed air (pressurized air) that has been pressurized by the first piston 24 inside the first pressure increase chamber 34 to the outlet port 14. The first pressure increase passage 40 has a check valve 40a. The check valve 40a allows the pressurized air to pass only in the direction out of the first pressure increase chamber 34. The first supply passage 38 and the first pressure increase passage 40 open to the end 22a of the partition wall portion 22 facing the first direction.

[0016] The second cylinder 20 has a second cylinder chamber 20a extending in the axial direction. A second piston 26 is accommodated in the second cylinder chamber 20a. The second piston 26 slides axially inside the second cylinder chamber 20a while airtightly dividing the second cylinder chamber 20a into a second drive chamber 42 and a second pressure booster chamber 44. The second drive chamber 42 is located on the second side of the second piston 26, and the second pressure booster chamber 44 is located on the first side of the second piston 26.

[0017] The second drive chamber 42 communicates with a second drive flow path 46. The second drive chamber 42 supplies and discharges compressed air (drive air) through the second drive flow path 46. One end of the second drive flow path 46 opens near the second end of the second cylinder chamber 20a, and the other end of the second drive flow path 46 is connected to the selector valve 30.

[0018] The second booster chamber 44 is separated from the second drive chamber 42 by the second piston 26. The second booster chamber 44 is in communication with a second supply flow path 48 and a second booster flow path 50. The second supply flow path 48 supplies compressed air that has flowed in from the inlet port 12 to the second booster chamber 44. The second supply flow path 48 is provided with a check valve 48a that allows compressed air to pass only in the direction toward the second booster chamber 44. The second booster flow path 50 is a flow path that allows compressed air (boosted air) from the second booster chamber 44, which has been boosted by the second piston 26, to flow out to the outlet port 14. The second booster flow path 50 is provided with a check valve 50a that allows boosted air to pass only in the direction toward the outlet port 14. The second supply flow path 48 and the second booster flow path 50 open to the second end 22b of the partition portion 22.

[0019] The partition wall portion 22 includes an inlet port 12 (see FIG. 2), an outlet port 14 (see FIG. 2), an insertion hole 54, a first pilot valve 56, a second pilot valve 58, and a plurality of flow paths. The insertion hole 54 is a hole through which the piston rod 28 is inserted and penetrates the partition wall portion 22 in the axial direction. The piston rod 28 is inserted through the insertion hole 54 so as to be slidable in the axial direction. A packing (not shown) is provided at a predetermined position of the insertion hole 54 to prevent leakage of compressed air through a gap between the insertion hole 54 and the piston rod 28.

[0020] The first pilot valve 56 is provided inside the partition wall portion 22 and is located near the first-direction end 22a of the partition wall portion 22. The first pilot valve 56 is a three-port valve and includes a first pilot piston 56a, a first switch 56b, and a first pilot exhaust port 56c. When pilot air is supplied, the first pilot piston 56a switches the first pilot valve 56 from a first position (see FIG. 1) to a second position (see FIG. 5). The first switch 56b protrudes from the first-direction end 22a of the partition wall portion 22 into the first booster chamber 34. When the first piston 24 is displaced near the stroke end in the second direction, the first switch 56b is pressed by the first piston 24, switching the first pilot valve 56 from the second position to the first position.

[0021] In the first position, the first pilot valve 56 connects the inlet port 12 and the second pilot piston 58a of the second pilot valve 58 via a pilot flow path 57, and supplies pilot air to the second pilot piston 58a of the second pilot valve 58. In the second position, the first pilot valve 56 connects the first pilot exhaust portion 56c and the second pilot piston 58a, and discharges the pilot air of the second pilot piston 58a from the first pilot exhaust portion 56c. The compressed air supplied from the inlet port 12 and passing through the pilot flow path 57 is called pilot air.

[0022] The second pilot valve 58 is provided inside the partition wall portion 22 and is located near the second-direction end 22b of the partition wall portion 22. The second pilot valve 58 is a three-port valve and includes a second pilot piston 58a, a second switch 58b, and a second pilot exhaust port 58c. When pilot air is supplied, the second pilot piston 58a switches the second pilot valve 58 from the second position (see FIG. 5) to the first position (see FIG. 1). The second switch 58b protrudes from the second-direction end 22b of the partition wall portion 22 into the second booster chamber 44. When the second piston 26 is displaced near the stroke end in the first direction, the second switch 58b is pressed by the second piston 26, switching the second pilot valve 58 from the first position to the second position.

[0023] In the first position, the second pilot valve 58 connects a second pilot exhaust portion 58c to the second switching piston 30b of the switching valve 30 and the first pilot piston 56a of the first pilot valve 56. That is, in the first position, the second pilot valve 58 exhausts pilot air from the second switching piston 30b and the first pilot piston 56a. In the second position, the second pilot valve 58 connects the inlet port 12 to the second switching piston 30b and the first pilot piston 56a. That is, in the second position, the second pilot valve 58 supplies pilot air to the second switching piston 30b and the first pilot piston 56a.

[0024] The first pilot valve 56 and the second pilot valve 58 are connected to the inlet port 12 via a pilot flow path 57. The pilot flow path 57 is a flow path formed inside the partition wall portion 22. The pilot flow path 57 branches off from a common drive flow path 60 and is connected to the inlet port 12 via the common drive flow path 60. In other words, the pilot flow path 57 takes in pilot air from the common drive flow path 60, which is a different system from the booster chamber supply flow path 13.

[0025] The common driving flow path 60 has an upstream end connected to the inlet port 12 and a downstream end connected to the switching valve 30. The common driving flow path 60 takes in compressed air from the inlet port 12 and guides it to the switching valve 30.

[0026] The switching valve 30 is a five-port valve connected to the common drive channel 60, two exhaust sections 16, the first drive channel 36, and the second drive channel 46. The switching valve 30 is displaced to the first position shown in FIG. 1 by the first switching piston 30a, and to the second position shown in FIG. 5 by the second switching piston 30b. When pilot air is not supplied to the first switching piston 30a, compressed air from the inlet port 12 flows around inside and is supplied, displacing the switching valve 30 to the first position. The second switching piston 30b is driven by pilot air supplied from the second pilot valve 58.

[0027] 1 , the switching valve 30 connects the common drive channel 60 to the second drive channel 46, and connects the first drive channel 36 to the exhaust channel 17. That is, in the first position, the switching valve 30 exhausts the compressed air in the first drive chamber 32 through the exhaust section 16 and supplies compressed air to the second drive chamber 42. In addition, in the second position shown in FIG. 5 , the switching valve 30 connects the common drive channel 60 to the first drive channel 36, and connects the second drive channel 46 to the exhaust channel 17. That is, in the second position, the switching valve 30 supplies compressed air to the first drive chamber 32 and exhausts compressed air from the second drive chamber 42.

[0028] The pressure intensifier 10 of this embodiment further includes a throttle portion 62 in the common drive flow path 60. The throttle portion 62 is provided in the common drive flow path 60 at a position downstream of the branch point with the pilot flow path 57. The throttle portion 62 limits the flow rate of compressed air supplied to the first drive chamber 32 or the second drive chamber 42 through the common drive flow path 60. The throttle portion 62 may be a fixed throttle, such as a throttle-equipped spacer 66 attached to a flow path member 64 (see FIG. 3 ). The throttle portion 62 may also be a variable throttle valve. The throttle portion 62 limits the flow rate of excess compressed air when the first piston 24 and the second piston 26 of the pressure intensifier 10 operate at high speed.

[0029] Specific configuration examples of the drive circuit (air circuit) and the switching valve 30 will be described below. As shown in Figures 2 and 3, the pressure booster 10 includes a flow path member 64 that connects the switching valve 30 and the partition wall portion 22. The switching valve 30 is attached to the upper part of the partition wall portion 22 via the flow path member 64. The flow path member 64 has a common drive flow path 60, a first drive flow path 36, a second drive flow path 46, and an exhaust portion 16. In Figure 2, the exhaust portion 16 of the flow path member 64 is covered by a porous sheet 16a that constitutes a sound-deadening member and a frame member 16b that holds the porous sheet 16a.

[0030] As shown in FIG. 3 , flow path member 64 has five openings 64a, 64b, 64c, 64d, and 64e at the connection portion with switching valve 30. Opening 64a communicates with exhaust section 16, opening 64b communicates with second drive flow path 46, opening 64c communicates with common drive flow path 60, opening 64d communicates with first drive flow path 36, and opening 64e communicates with exhaust section 16 via exhaust path 17. A throttled spacer 66 serving as throttle section 62 is attached to opening 64c. The throttled spacer 66 is attached so as to close opening 64c. A throttle hole 66a is provided in the center of throttle spacer 66. The throttle hole 66a penetrates throttle spacer 66 in the thickness direction.

[0031] As shown in FIG. 4 , the effective cross-sectional area of ​​the throttle hole 66 a of the throttle spacer 66 is smaller than the effective cross-sectional area of ​​the common driving flow path 60 inside the flow path member 64. Therefore, the throttle spacer 66 throttles the flow rate of the driving air before supplying it to the switching valve 30. Such throttle spacers 66 are easily assembled because they can be added simply by fitting them into the predetermined openings 64 c of the flow path member 64. They can also be flexibly attached or detached according to user preference. Furthermore, the throttle spacers 66 located upstream of the switching valve 30 can trap and remove foreign matter that may be mixed into the compressed air by, for example, forming a mesh-like hole. This can also be expected to have an additional effect of preventing malfunctions. Furthermore, the throttle spacers 66 located near the switching valve 30 generate heat due to adiabatic compression. The heat generated by the throttle spacers 66 is transmitted to the adjacent switching valve 30, mitigating the temperature drop caused by adiabatic expansion inside the switching valve 30 and suppressing condensation near the switching valve 30.

[0032] The pressure booster 10 according to the first embodiment is configured as described above. The operation of the pressure booster 10 will now be described.

[0033] 1 shows a first stroke in which the first piston 24 and the second piston 26 of the pressure intensifier 10 move in a first direction. During the first stroke, compressed air is supplied to the first pressure intensifier chamber 34 of the first piston 24, and the first drive chamber 32 is connected to the exhaust section 16 via the exhaust passage 17 by the switching valve 30. The first piston 24 generates a driving force in the first direction due to the pressure difference between the first pressure intensifier chamber 34 and the first drive chamber 32. This driving force displaces the second piston 26 in the first direction. Compressed air is supplied to the second drive chamber 42 of the second cylinder 20 via the switching valve 30 and the second drive passage 46. The second piston 26 is displaced in the first direction by the driving force of the first piston 24, further compressing the compressed air in the second pressure intensifier chamber 44. The compressed air compressed in the second pressure intensifier chamber 44 is output to the outlet port 14 through the check valve 50a.

[0034] Thus, in the pressure intensifier 10, the first cylinder 18 serves as the driving cylinder and the second cylinder 20 serves as the booster cylinder during the first stroke. During the first stroke, the flow rate of compressed air flowing into the second driving chamber 42 is restricted by the throttle portion 62 (throttle spacer 66). The restriction of the flow rate by the throttle portion 62 becomes stronger the faster the first piston 24 and the second piston 26 of the pressure intensifier 10 operate. That is, the greater the flow rate of the driving air (compressed air used to drive the pressure intensifier 10), the more strongly the throttle portion 62 restricts the flow rate of compressed air flowing into the second driving chamber 42. The restriction of the flow rate by the throttle portion 62 is performed without requiring a movable mechanism. As a result, under operating conditions in which a large flow rate of boosted air is output, the pressure intensifier 10 can reduce the amount of compressed air (driving air) consumed during the first stroke.

[0035] On the other hand, the first drive flow path 36, which exhausts the compressed air from the first drive chamber 32, and the flow path leading to the exhaust section 16 in the pressure intensifier 10 are not restricted, and the compressed air from the first drive chamber 32 is smoothly exhausted. Therefore, the restriction section 62 does not reduce the stroke speed in the first direction of the pressure intensifier 10. For this reason, by providing the restriction section 62 in the common drive flow path 60, the pressure intensifier 10 reduces waste of compressed air (drive air) without reducing the operating speed (flow rate of the pressure intensifier air) under operating conditions in which a large flow rate of pressure intensifier air is output.

[0036] When the second piston 26 approaches the stroke end during the first stroke, the second switch 58b of the second pilot valve 58 is pressed by the second piston 26. As a result, the second pilot valve 58 is displaced to the second position. In the second position, the second pilot valve 58 connects the pilot flow path 57 to the second switching piston 30b and the first pilot piston 56a, and supplies pilot air to the first pilot valve 56 and the switching valve 30. As a result, the switching valve 30 and the first pilot valve 56 are displaced to the second position (see FIG. 5).

[0037] 5 , in the second position, the selector valve 30 connects the first drive chamber 32 to the common drive channel 60 and connects the second drive chamber 42 to the exhaust section 16. As a result, compressed air is supplied to the first drive chamber 32, and the compressed air in the second drive chamber 42 is exhausted from the exhaust section 16. Compressed air is supplied to the first booster chamber 34 and the second booster chamber 44 through the booster chamber supply channel 13. The second piston 26 generates a driving force in the second direction due to the pressure difference between the second booster chamber 44 and the second drive chamber 42, and the first piston 24 and the second piston 26 begin a stroke in the second direction (second stroke).

[0038] During the second stroke, the first cylinder 18 functions as a booster cylinder, and the second cylinder 20 functions as a drive cylinder. During the second stroke, compressed air is supplied to the first drive chamber 32 through the first drive flow path 36 and the common drive flow path 60. The flow rate of the compressed air supplied to the first drive chamber 32 is throttled by a throttle section 62 provided in the common drive flow path 60. Under operating conditions in which the first piston 24 and the second piston 26 of the booster device 10 operate at high speed, the throttle section 62 throttles the flow rate of drive air flowing into the first drive chamber 32. As a result, the booster device 10 can reduce the amount of compressed air consumed during the second stroke as well.

[0039] Furthermore, during the second stroke, the compressed air in the second drive chamber 42 is quickly exhausted without being affected by the throttle portion 62. Therefore, the throttle portion 62 does not reduce the operating speed (reciprocation frequency) of the second stroke of the pressure booster device 10.

[0040] During the second stroke shown in FIG. 5 , when the first piston 24 reaches near the stroke end, the first switch 56b of the first pilot valve 56 is pressed by the first piston 24, causing the first pilot valve 56 to move to the first position shown in FIG. 1 . In the first position, the first pilot valve 56 supplies pilot air to the second pilot piston 58a of the second pilot valve 58, causing the second pilot valve 58 to move to the first position. In the first position, the second pilot valve 58 exhausts pilot air from the switching valve 30 and the first pilot valve 56 through the second pilot exhaust port 58c. As a result, the switching valve 30 moves to the first position, and the first stroke described with reference to FIG. 1 is performed. Thereafter, the pressure booster 10 alternately performs the first stroke and the second stroke to boost the compressed air.

[0041] A simulation calculation was conducted to examine the changes in pressure in the first drive chamber 32 and the second drive chamber 42 that accompany the operation of the pressure intensifier 10 according to the present embodiment. The results are shown in Figures 6A and 6B. As shown by the dashed line 68 in Figure 6A, the displacement speed of the first piston 24 and the second piston 26 did not change between the case where the throttle portion 62 was provided and the case where the throttle portion 62 was not provided, and the operating speed did not decrease.

[0042] 6A and 6B, curve 70 represents the pressure transition in the first drive chamber 32, and curve 72 represents the pressure transition in the second drive chamber 42. As shown in Fig. 6B, the pressure transition in the first drive chamber 32 when the throttle section 62 is provided (curve 70) is lower than the pressure transition in the first drive chamber 32 when the throttle section 62 is not provided (curve 70a, comparative example). This result indicates that the throttle section 62 suppresses the supply of excessive compressed air to the first drive chamber 32, thereby suppressing the consumption of compressed air.

[0043] As described above, the booster device 10 of this embodiment can reduce the amount of compressed air consumed without reducing the operating speed. Furthermore, by restricting the flow rate of compressed air, the outflow of grease from the inside of the switching valve 30 can be reduced, thereby reducing the effort required for maintenance.

[0044] The restrictor portion 62 of this embodiment is not limited to the restrictor spacer 66. The restrictor portion 62 may be configured with a sensor element that detects the pressure at the outlet port 14 and a throttle valve that variably adjusts the effective cross-sectional area in accordance with the output of the sensor element. The restrictor portion 62 of this form may operate to reduce the flow rate of compressed air passing through the common driving flow path 60 as the flow rate at the outlet port 14 increases.

[0045] 7A, a pressure intensifier 10A according to this embodiment differs from the pressure intensifier 10 described with reference to FIGS. 1 to 5 in that the pilot flow path 57 is connected to the common driving flow path 60 at a position downstream of the throttle section 62. Note that, in the configuration of each part of the pressure intensifier 10A, components similar to those of the pressure intensifier 10 described with reference to FIGS. 1 to 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0046] As shown in Fig. 7A, the pilot flow path 57 is connected to the common driving flow path 60 at a portion between the throttle portion 62 and the switching valve 30. Fig. 7B is a cross-sectional view of the partition wall 22 of the pressure booster 10A. As shown in Fig. 7B, the common driving flow path 60 extends upward from the inlet port 12 inside the partition wall 22 and is connected to the inside of a flow path member 64. In this embodiment, a throttle portion 62 is formed in the partition wall 22 as a narrowed section 74 that reduces the effective cross-sectional area of ​​the common driving flow path 60. The pilot flow path 57 is connected to the common driving flow path 60 inside the flow path member 64, and is connected to the common driving flow path 60 downstream of the throttle portion 62.

[0047] The pressure intensifier 10A of this embodiment can reduce the amount of compressed air consumed, similar to the pressure intensifier 10. Furthermore, the pressure intensifier 10A does not require an additional component such as the throttle spacer 66, and therefore the assembly work can be simplified.

[0048] 8, a pressure intensifier 10B of this embodiment differs from the pressure intensifier 10 described with reference to FIGS. 1 to 5 in the position of the throttle portion 62. Note that, among the configurations of the components of the pressure intensifier 10B, components similar to those of the pressure intensifier 10 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0049] 8, the pressure booster 10B has a first throttle section 62A and a second throttle section 62B. The first throttle section 62A is provided in the first drive flow path 36, and the second throttle section 62B is provided in the second drive flow path 46. The first throttle section 62A throttles the flow rate of compressed air (drive air) flowing into the first drive chamber 32 through the first drive flow path 36. The second throttle section 62B throttles the flow rate of compressed air (drive air) flowing into the second drive chamber 42 through the second drive flow path 46.

[0050] Because the first throttle section 62A and the second throttle section 62B do not have directionality, they may hinder the exhaust of compressed air from the first drive chamber 32 or the second drive chamber 42, which could reduce the operating speed of the pressure intensifier 10B. Therefore, the pressure intensifier 10B includes a first check valve 78A connected in parallel to the first throttle section 62A and a second check valve 78B connected in parallel to the second throttle section 62B. The first check valve 78A allows compressed air to pass only in the direction from the first drive chamber 32 to the exhaust section 16 and prevents compressed air from passing in the reverse direction. The second check valve 78B allows compressed air to pass only in the direction from the second drive chamber 42 to the exhaust section 16 and prevents compressed air from passing in the reverse direction. The first check valve 78A and the second check valve 78B enable smooth exhaust of compressed air and prevent a reduction in the operating speed of the pressure intensifier 10B.

[0051] To enable smooth exhaust, it is preferable that the first check valve 78A and the second check valve 78B have exhaust flow characteristics that are equal to or greater than those of the switching valve 30. The first throttle section 62A and the first check valve 78A, and the second throttle section 62B and the second check valve 78B can be configured as an integrated throttle with check valve 80, for example, as shown in Figures 9 and 10.

[0052] 9 , the first cylinder 18 and the partition wall 22 of this embodiment have large-diameter passage holes 82a, 82b extending in the axial direction. The large-diameter passage holes 82a, 82b constitute part of the first drive passage 36. A restrictor 80 with a check valve is attached to the large-diameter passage hole 82b of the partition wall 22 in a portion adjacent to the first cylinder 18.

[0053] As shown in Figure 10, the throttle with check valve 80 comprises a cylindrical body 80a, a valve body 80c, a lid portion 80d, and a biasing member 80e. The cylindrical body 80a is formed in a cylindrical shape and has a cylindrical hole 80f therein through which compressed air passes. An inwardly protruding seat portion 80b is formed at one end of the cylindrical body 80a. A communication hole 80g that communicates with the cylindrical hole 80f is formed in the seat portion 80b.

[0054] The valve element 80c is housed in the cylindrical bore 80f. The valve element 80c is sandwiched between the lid portion 80d and the seat portion 80b and is movable between them. The valve element 80c is pressed against the seat portion 80b by a biasing member 80e supported by the lid portion 80d. Therefore, in the initial state, the tip of the valve element 80c is in contact with the seat portion 80b without any gap. The valve element 80c has a throttle hole 80h in its center, which throttles the flow path of compressed air from the lid portion 80d toward the communication hole 80g. This throttle hole 80h forms the throttle section 62 (first throttle section 62A).

[0055] When the valve element 80c receives a flow of compressed air from the communication hole 80g toward the lid portion 80d, it moves away from the seat portion 80b. As a result, the valve element 80c allows a larger flow rate of compressed air to pass through the gap between the valve element 80c and the seat portion 80b than through the throttle hole 80h. Therefore, the valve element 80c functions as the first check valve 78A, allowing the compressed air to flow in a predetermined direction without restriction.

[0056] Furthermore, the second cylinder 20 and the partition wall 22 of this embodiment have large-diameter flow passage holes 84a, 84b extending in the axial direction as part of the second drive flow passage 46. The above-mentioned throttle with check valve 80 is attached to the large-diameter flow passage hole 84b. The throttle with check valve 80 in the large-diameter flow passage hole 84b is attached in the opposite direction to the throttle with check valve 80 in the large-diameter flow passage hole 82b.

[0057] The pressure booster 10B of this embodiment configured as described above also provides the same effects as the pressure booster 10 of the first embodiment.

[0058] 11 and 12A , a pressure intensifier 10C of this embodiment has a first cylinder 90, a third cylinder 92, and a second cylinder 94 that are connected side by side in the axial direction. The first cylinder 90 is located on a first axial direction side, the third cylinder 92 is located on a second axial direction side, and the second cylinder 94 is disposed between the first cylinder 90 and the third cylinder 92.

[0059] The first cylinder 90 has a first cylinder chamber 96 extending in the axial direction and a first piston 98 housed in the first cylinder chamber 96. The first piston 98 slides axially inside the first cylinder chamber 96. The first piston 98 divides the first cylinder chamber 96 into a first drive chamber 96a on the first direction side and a second drive chamber 96b on the second direction side. A first end 100a of a piston rod 100 is joined to the first piston 98.

[0060] The second cylinder 94 has a second cylinder chamber 102 extending axially therein and a second piston 104 housed in the second cylinder chamber 102. The second piston 104 slides axially inside the second cylinder chamber 102. The second piston 104 divides the second cylinder chamber 102 into a first pressure increase chamber 102a on the first direction side and a second pressure increase chamber 102b on the second direction side. The second piston 104 is joined to the axial center of the piston rod 100.

[0061] The third cylinder 92 has a third cylinder chamber 106 extending in the axial direction and a third piston 108 housed in the third cylinder chamber 106. The third piston 108 slides axially inside the third cylinder chamber 106. The third piston 108 divides the third cylinder chamber 106 into a third drive chamber 106a on the first direction side and a fourth drive chamber 106b on the second direction side. The third piston 108 is joined to an end 100b of the piston rod 100 on the second direction side.

[0062] The first piston 98, the second piston 104, and the third piston 108 are axially connected to one another by a piston rod 100 and move integrally in the axial direction. The first piston 98, the second piston 104, and the third piston 108 are driven by compressed air supplied to and discharged from the first cylinder 90 and the third cylinder 92 through a drive circuit 109. The drive circuit 109 includes a first selector valve 110 and a second selector valve 114 provided on the first cylinder 90, the second cylinder 94, and the third cylinder 92 (see FIG. 12A). The drive circuit 109 of the pressure booster 10C will be described below.

[0063] The drive circuit 109 of the pressure intensifier 10C includes an inlet port 12, an outlet port 14, a first switching valve 110, a first pilot valve 112, a second switching valve 114, and a second pilot valve 116. Compressed air supplied from a compressed air supply system flows into the inlet port 12. The inlet port 12 is connected to the first drive path 36, the second drive path 46, the first boosted supply path 118, and the second boosted supply path 120. The first drive path 36 is connected to the first switching valve 110. A first throttle section 62A is provided in the first drive path 36. The first throttle section 62A reduces the flow rate of compressed air supplied to the first cylinder 90 when the pressure intensifier 10C operates at high speed and high frequency, preventing unnecessary supply of compressed air.

[0064] The second drive flow path 46 is connected to the second selector valve 114 and supplies compressed air to the second selector valve 114. A second throttle section 62B is provided in the second drive flow path 46. The second throttle section 62B reduces the flow rate of compressed air supplied to the third cylinder 92 when the pressure intensifier 10C operates at high speed and high frequency, thereby preventing unnecessary supply of compressed air. As shown in FIG. 12B , the second throttle section 62B can be formed, for example, by reducing the inner diameter of a portion of the flow path fixed between the third cylinder 92 and the second selector valve 114.

[0065] The first booster supply passage 118 connects the inlet port 12 and the first booster chamber 102a of the second cylinder 94 and supplies compressed air to the first booster chamber 102a. The first booster supply passage 118 is provided with a check valve 118a that allows compressed air to pass only in the direction from the inlet port 12 toward the first booster chamber 102a. The check valve 118a prevents the compressed air boosted in the first booster chamber 102a from flowing back into the inlet port 12.

[0066] The second booster supply passage 120 connects the inlet port 12 and the second booster chamber 102b of the second cylinder 94, and supplies compressed air to the second booster chamber 102b. The second booster supply passage 120 is provided with a check valve 120a that allows compressed air to pass only in the direction from the inlet port 12 toward the second booster chamber 102b. The check valve 120a prevents the compressed air that has been boosted in the second booster chamber 102b from flowing back into the inlet port 12.

[0067] The first switching valve 110 is a five-port valve. A first end of the first switching valve 110 is connected to the first drive flow path 36, a first exhaust path 122, and a first exhaust return path 124, and a second end of the first switching valve 110 is connected to a first drive chamber flow path 126 and a second drive chamber flow path 128. The first exhaust path 122 exhausts compressed air used in the first cylinder 90. The first exhaust path 122 is connected to an exhaust section 132 via an exhaust resistor 130. The exhaust section 132 releases the compressed air in the first exhaust path 122 into the atmosphere via a predetermined silencer.

[0068] The first exhaust return flow path 124 is a flow path branching off from the first driving chamber flow path 126. The first exhaust return flow path 124 introduces a portion of the compressed air discharged from the first driving chamber 96a into the second driving chamber 96b during the first stroke in which the first piston 98 is displaced in the first direction. Details of the first exhaust return flow path 124 or the second exhaust return flow path 136 are also described in Japanese Patent No. 6938829. The description of the exhaust return circuit in Japanese Patent No. 6938829 is incorporated as part of the description of this embodiment.

[0069] The first drive chamber flow path 126 connects the first selector valve 110 and the first drive chamber 96 a. The first drive chamber flow path 126 supplies or discharges compressed air to or from the first drive chamber 96 a. The second drive chamber flow path 128 connects the first selector valve 110 and the second drive chamber 96 b. The second drive chamber flow path 128 supplies or discharges compressed air to or from the second drive chamber 96 b.

[0070] The first selector valve 110 is driven by pilot air. When pilot air is supplied to the first selector valve 110, the first selector valve 110 is displaced to the first position shown in the figure, connecting the first drive flow path 36 to the first drive chamber flow path 126 and connecting the first exhaust path 122 to the second drive chamber flow path 128. In this case, compressed air is supplied to the first drive chamber 96a, causing the first piston 98 to generate a driving force in the second direction and perform a stroke in the second direction.

[0071] When the pilot air of the first switching valve 110 is discharged, the first switching valve 110 is displaced to the second position. In the second position, the first switching valve 110 connects the first exhaust passage 122 to the first drive chamber passage 126 and connects the first exhaust return passage 124 to the second drive chamber passage 128. This discharges the compressed air from the first drive chamber 96a, causing the first piston 98 to stroke in the first direction. During the stroke in the first direction, the first exhaust return passage 124 introduces a portion of the compressed air from the first drive chamber 96a into the second drive chamber 96b. As a result, the first cylinder 90 strokes in the first direction without consuming compressed air.

[0072] The second switching valve 114 is a five-port valve. A first end of the second switching valve 114 is connected to the second drive flow path 46, the second exhaust path 134, and the second exhaust return path 136, and a second end of the second switching valve 114 is connected to the third drive chamber flow path 138 and the fourth drive chamber flow path 140. The second exhaust path 134 exhausts compressed air used in the third cylinder 92. The second exhaust path 134 is connected to the exhaust section 132 via the exhaust resistor 130. The exhaust section 132 releases the compressed air in the second exhaust path 134 into the atmosphere via a predetermined silencer.

[0073] The second exhaust return passage 136 is a passage branching off from the fourth drive chamber passage 140. The second exhaust return passage 136 introduces a portion of the compressed air discharged from the fourth drive chamber 106b into the third drive chamber 106a during the second stroke in which the third piston 108 is displaced in the second direction.

[0074] The third drive chamber flow path 138 connects the second selector valve 114 and the third drive chamber 106 a. The third drive chamber flow path 138 supplies or discharges compressed air to or from the third drive chamber 106 a. The fourth drive chamber flow path 140 connects the second selector valve 114 and the fourth drive chamber 106 b. The fourth drive chamber flow path 140 supplies or discharges compressed air to or from the fourth drive chamber 106 b.

[0075] The second switching valve 114 is driven by pilot air. When pilot air is not supplied to the second switching valve 114, the second switching valve 114 is located in the first position shown in the figure. When the second switching valve 114 is in the first position, it connects the second exhaust return passage 136 to the third drive chamber passage 138 and also connects the second exhaust passage 134 to the fourth drive chamber passage 140. In this case, the second exhaust return passage 136 introduces a portion of the compressed air in the fourth drive chamber 106b into the third drive chamber 106a. As a result, the third cylinder 92 performs a stroke in the second direction without consuming compressed air.

[0076] When pilot air is supplied to second selector valve 114, second selector valve 114 is displaced to the second position. In the second position, second selector valve 114 connects second exhaust passage 134 to third drive chamber passage 138 and connects second drive passage 46 to fourth drive chamber passage 140. As a result, compressed air is exhausted from third drive chamber 106a and supplied to fourth drive chamber 106b, causing third piston 108 to generate a driving force in the first direction and perform a first stroke in the first direction.

[0077] Pilot air is supplied to and discharged from the first switching valve 110 and the second switching valve 114 by a first pilot valve 112 and a second pilot valve 116. The first pilot valve 112 and the second pilot valve 116 are three-port valves. A first pilot input passage 142 and a pilot exhaust port 144 are connected to a first end of the first pilot valve 112, and a first pilot output passage 146 is connected to a second end of the first pilot valve 112.

[0078] The first pilot input path 142 branches off from the first drive path 36 and guides compressed air (pilot air) to the first pilot valve 112. The pilot exhaust section 144 exhausts the pilot air to the atmosphere. The first pilot output path 146 supplies pilot air to the second switching valve 114 and the second pilot valve 116.

[0079] In the illustrated first position, the first pilot valve 112 connects the pilot exhaust portion 144 to the first pilot output path 146. That is, the first pilot valve 112 in the first position exhausts pilot air from the second switching valve 114 and the second pilot valve 116. In the second position, the first pilot valve 112 connects the first pilot input path 142 to the first pilot output path 146. That is, the first pilot valve 112 in the second position supplies pilot air to the second switching valve 114 and the second pilot valve 116.

[0080] The first pilot valve 112 includes a first pilot piston 112a and a switch 112b. The first pilot piston 112a receives a supply of pilot air and displaces the first pilot valve 112 to the illustrated first position. The switch 112b protrudes in the first direction from the second-direction end of the second drive chamber 96b. The switch 112b abuts against the first piston 98 near the end of the second stroke and is pressed in the second direction, displacing the first pilot valve 112 to the second position.

[0081] A first end of the second pilot valve 116 is connected to a second pilot input passage 148 and the pilot exhaust 144, and a second end of the second pilot valve 116 is connected to a second pilot output passage 150.

[0082] A second pilot input path 148 branches off from the second drive path 46 and guides compressed air (pilot air) to the second pilot valve 116. The pilot exhaust section 144 exhausts the pilot air. A second pilot output path 150 guides the pilot air to the first switching valve 110 and the first pilot valve 112.

[0083] In the illustrated first position, the second pilot valve 116 communicates between the second pilot input path 148 and the second pilot output path 150. That is, the second pilot valve 116 in the first position supplies pilot air to the first switching valve 110 and the first pilot valve 112. In the second position, the second pilot valve 116 communicates between the pilot exhaust portion 144 and the second pilot output path 150. That is, the second pilot valve 116 in the second position exhausts pilot air from the first switching valve 110 and the first pilot valve 112.

[0084] The second pilot valve 116 includes a second pilot piston 116a and a switch 116b. The second pilot piston 116a receives a supply of pilot air and displaces the second pilot valve 116 to a second position. The switch 116b protrudes in the second direction from the first-direction end of the third drive chamber 106a. The switch 116b abuts against the third piston 108 near the end of the first stroke and is pressed in the first direction, displacing the second pilot valve 116 to the illustrated first position.

[0085] The booster device 10C drives the second piston 104 by the drive circuit 109, and the second piston 104 alternately performs a first stroke in a first direction and a second stroke in a second direction. During the first stroke, compressed air is compressed in the first booster chamber 102a. Compressed air is supplied to the second booster chamber 102b. The compressed air compressed in the first booster chamber 102a is discharged from the outlet port 14 through the first booster output path 152. The first booster output path 152 is provided with a check valve 152a that allows the boosted compressed air to pass only in the direction toward the outlet port 14. The check valve 152a prevents backflow of the boosted compressed air.

[0086] During the second stroke, compressed air is compressed in the second pressure booster chamber 102b. Compressed air is supplied to the first pressure booster chamber 102a. The compressed air compressed in the second pressure booster chamber 102b is discharged from the outlet port 14 through the second pressure booster output path 154. The second pressure booster output path 154 is provided with a check valve 154a that allows the pressurized compressed air to pass only in the direction toward the outlet port 14. The check valve 154a prevents the pressurized compressed air from flowing backward.

[0087] The pressure intensifier 10C of this embodiment configured as described above limits the flow rate of compressed air flowing into the first cylinder 90 using the first throttle section 62A during high-speed and high-frequency operation. Furthermore, the pressure intensifier 10C limits the flow rate of compressed air flowing into the third cylinder 92 using the second throttle section 62B during high-speed and high-frequency operation. Therefore, the pressure intensifier 10C can prevent excessive compressed air from flowing in during high-speed and high-frequency operation, thereby reducing the amount of compressed air consumed. Furthermore, because the first throttle section 62A does not impede the exhaust of the first cylinder 90, and the second throttle section 62B does not impede the exhaust of the third cylinder 92, the operating speed of the pressure intensifier 10C is not reduced.

[0088] The following additional notes are further disclosed regarding the above embodiment.

[0089] (Supplementary Note 1) One aspect of the above disclosure is a pressure booster device 10 comprising: an inlet port 12 through which compressed air flows in; drive chambers 32, 42 that drive a first piston 24 with the compressed air flowing in from the inlet port; a second piston 26 connected to the first piston; pressure booster chambers 34, 44 in which the compressed air is compressed by the second piston; an outlet port 14 through which the compressed air compressed in the pressure booster chamber flows out; an exhaust section 16 that exhausts the compressed air from the drive chamber; and a selector valve 30 that selects and connects the inlet port or the exhaust section to the drive chamber, and a throttle section 62 in a flow path connecting the inlet port and the drive chamber that restricts the flow rate of the compressed air heading toward the drive chamber and does not hinder the discharge of the compressed air from the drive chamber.

[0090] The above-mentioned booster device has a throttle portion that limits the flow rate of compressed air toward the drive chamber. When the flow rate of the booster device increases, the throttle portion limits the inflow of excess compressed air into the drive chamber, thereby reducing the waste of compressed air. Furthermore, the throttle portion does not impede the flow of compressed air discharged from the drive chamber to the exhaust port or the flow of compressed air supplied to or discharged from the booster chamber. Therefore, the above-mentioned booster device can reduce the consumption of compressed air while maintaining the flow rate of boosted air.

[0091] (Supplementary Note 2) In the pressure booster device according to Supplementary Note 1, the throttle portion may be provided in a flow path connecting the inlet port and the switching valve, and the effective cross-sectional area of ​​the throttle portion may be smaller than the effective cross-sectional area of ​​an exhaust path 17 connecting the switching valve and the exhaust portion. This pressure booster device can reduce unnecessary consumption of compressed air without reducing operating speed by restricting only the supply of compressed air to the drive chamber without interfering with exhaust from the drive chamber.

[0092] (Supplementary Note 3) In the pressure intensifier according to Supplementary Note 1 or 2, the throttle portion may be provided in a flow path connecting the switching valve and the drive chamber, and a check valve may be provided in parallel with the throttle portion and allow the compressed air to pass only in a direction from the drive chamber to the switching valve. This pressure intensifier can also reduce the amount of compressed air consumed when operating at high speeds and high frequencies.

[0093] (Supplementary Note 4) In the pressure booster according to any one of Supplementary Notes 1 to 3, the throttle section may be a variable throttle valve. This pressure booster can flexibly adjust the flow rate of the throttle section in accordance with operating conditions such as the input pressure, boost ratio, and discharge flow rate, thereby effectively reducing the amount of compressed air consumed.

[0094] (Supplementary Note 5) A pressure booster device according to any one of Supplementary Notes 1 to 4, comprising: a first cylinder 18 accommodating the first piston; a second cylinder 20 accommodating the second piston; a partition wall 22 disposed between the first cylinder and the second cylinder; and a piston rod 28 inserted through the partition wall and connecting the first piston and the second piston, wherein the drive chamber has a first drive chamber 32 partitioned by the first piston inside the first cylinder and a second drive chamber 42 partitioned by the second piston inside the second cylinder, and the pressure booster chamber is separated from the first drive chamber by the first piston inside the first cylinder. a first booster chamber (34) separated from the second drive chamber by the second piston within the second cylinder, a common drive channel (60) connecting the inlet port and the selector valve, a first drive channel (36) connecting the first drive chamber and the selector valve, and a second drive channel (46) connecting the second drive chamber and the selector valve, the selector valve being switchable between a first position which connects the common drive channel and the first drive channel and also connects the exhaust port and the second drive channel, and a second position which connects the common drive channel and the second drive channel and also connects the exhaust port and the first drive channel. This booster device can also reduce the amount of compressed air consumed during high-speed and high-frequency operation.

[0095] (Supplementary Note 6) In the pressure booster device according to Supplementary Note 5, the throttle portion may be provided in the common driving flow path. Since this pressure booster device requires only one throttle portion, the number of parts can be reduced and the device configuration can be made smaller.

[0096] (Supplementary Note 7) In the pressure intensifier described in Supplementary Note 5, the throttle section may include a first throttle section (62A) provided in the first drive flow path, a second throttle section (62B) provided in the second drive flow path, a first check valve (78A) connected to the first drive flow path in parallel with the first throttle section and configured to pass the compressed air only in a direction toward the exhaust section, and a second check valve (78B) connected to the second drive flow path in parallel with the second throttle section and configured to pass the compressed air only in a direction toward the exhaust section. This pressure intensifier can also reduce the amount of compressed air consumed during high-speed and high-frequency operation.

[0097] (Supplementary Note 8) The booster device described in Supplementary Note 5 may include a pilot flow path 57 branched from the common drive flow path, and pilot valves 56, 58 that supply the compressed air in the pilot flow path as pilot air to the switching valve. This booster device enables stable operation by taking in pilot air from the common drive flow path, which is a flow path separate from the booster chamber supply flow path.

[0098] (Supplementary Note 9) In the pressure intensifier according to Supplementary Note 8, the throttle portion may be provided in the common driving channel and located downstream of the pilot channel and the common driving channel. In this pressure intensifier, the flow rate of the pilot channel is not throttled by the throttle portion, so that a time delay in the switching operation of the switching valve can be prevented and a decrease in the discharge capacity of the boosted air can be prevented.

[0099] (Supplementary Note 10) In the pressure intensifier according to Supplementary Note 8, the throttle portion may be provided in the common drive flow path and located upstream of the pilot flow path and the common drive flow path. In this pressure intensifier, the throttle portion can be formed by processing the flow path of the partition wall, and the throttle portion can be provided without adding or assembling parts.

[0100] (Supplementary Note 11) The pressure booster device according to any one of Supplementary Notes 1 to 4 may include a first cylinder (90) that accommodates the first piston, a second cylinder (94) that is connected to the first cylinder and accommodates the second piston, a third cylinder (92) that is connected to the second cylinder and accommodates a third piston (108), and a piston rod (100) that connects the first piston, the second piston, and the third piston, wherein the switching valve includes a first switching valve (110) that switches between connecting the inlet port or the exhaust unit to the first cylinder, and a second switching valve (114) that switches between connecting the inlet port or the exhaust unit to the third cylinder, and the throttle unit may include a first throttle unit (62A) that is provided in a first drive flow path (36) that connects the inlet port and the first switching valve, and a second throttle unit (62B) that is provided in a second drive flow path (46) that connects the inlet port and the second switching valve. This pressure booster also reduces the amount of compressed air consumed during high-speed and high-frequency operation.

[0101] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

Claims

1. A pressure booster (10) comprising: an inlet port (12) into which compressed air flows; a drive chamber (32, 42) that drives a first piston (24) with the compressed air flowing in from the inlet port; a second piston (26) connected to the first piston; a pressure booster chamber (34, 44) in which the compressed air is compressed by the second piston; an outlet port (14) from which the compressed air compressed in the pressure booster chamber flows out; an exhaust section (16) that exhausts the compressed air from the drive chamber; and a switching valve (30) that selects and connects the inlet port or the exhaust section to the drive chamber, and a throttle section (62) in a flow path connecting the inlet port and the drive chamber that limits the flow rate of the compressed air heading toward the drive chamber and does not hinder the discharge of the compressed air from the drive chamber.

2. A pressure booster according to claim 1, wherein the throttle portion is provided in a flow path connecting the inlet port and the switching valve, and the effective cross-sectional area of ​​the throttle portion is smaller than the effective cross-sectional area of ​​an exhaust path (17) connecting the switching valve and the exhaust portion.

3. A pressure booster according to claim 1, wherein the throttle section is provided in a flow path connecting the switching valve and the drive chamber, and a check valve is provided in parallel with the throttle section and allows the compressed air to pass only in the direction from the drive chamber toward the switching valve.

4. A pressure intensifier according to claim 1, wherein the throttle portion is a variable throttle valve.

5. A pressure booster device according to any one of claims 1 to 4, comprising: a first cylinder (18) accommodating the first piston; a second cylinder (20) accommodating the second piston; a partition (22) disposed between the first cylinder and the second cylinder; and a piston rod (28) passing through the partition and connecting the first piston and the second piston; the drive chamber has: a first drive chamber (32) separated by the first piston inside the first cylinder; and a second drive chamber (42) separated by the second piston inside the second cylinder; the pressure booster chamber has: a first pressure booster chamber (34) separated from the first drive chamber by the first piston inside the first cylinder; and a second pressure booster chamber (44) separated from the second drive chamber by the second piston inside the second cylinder; a common drive flow path (60) connecting the inlet port and the switching valve; a first drive flow path (36) connecting the first drive chamber and the switching valve; and a second drive flow path (46) connecting the second drive chamber and the switching valve, wherein the switching valve is switchable between a first position that connects the common drive flow path and the first drive flow path and also connects the exhaust section and the second drive flow path, and a second position that connects the common drive flow path and the second drive flow path and also connects the exhaust section and the first drive flow path.

6. A pressure intensifier according to claim 5, wherein the throttle portion is provided in the common drive flow path.

7. A pressure booster according to claim 5, wherein the throttling section comprises: a first throttling section (62A) provided in the first drive flow path; a second throttling section (62B) provided in the second drive flow path; a first check valve (78A) connected in parallel to the first throttling section in the first drive flow path and allowing the compressed air to pass only in the direction towards the exhaust section; and a second check valve (78B) connected in parallel to the second throttling section in the second drive flow path and allowing the compressed air to pass only in the direction towards the exhaust section.

8. A pressure booster according to claim 5, comprising a pilot flow path (57) branching off from the common drive flow path, and pilot valves (56, 58) that supply the compressed air in the pilot flow path to the switching valve as pilot air.

9. A pressure intensifier according to claim 8, wherein the throttle portion is provided in the common drive flow passage and is located downstream of the pilot flow passage and the common drive flow passage.

10. A pressure intensifier according to claim 8, wherein the throttle portion is provided in the common drive flow passage and is located upstream of the pilot flow passage and the common drive flow passage.

11. A pressure booster according to any one of claims 1 to 4, comprising: a first cylinder (90) accommodating the first piston; a second cylinder (94) connected to the first cylinder and accommodating the second piston; a third cylinder (92) connected to the second cylinder and accommodating a third piston; and a piston rod (100) connecting the first piston, the second piston, and the third piston; the switching valve comprising: a first switching valve (110) that switches between connecting the inlet port or the exhaust part to the first cylinder; and a second switching valve (114) that switches between connecting the inlet port or the exhaust part to the third cylinder; and the throttle portion comprising: a first throttle portion (62A) provided in a first drive flow path (36) that connects the inlet port and the first switching valve; a second throttle portion (62B) provided in a second drive flow path (46) connecting the inlet port and the second switching valve.

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