Thrust Augmentation Device

Abstract

To adjust a movable range of an input rod of an air cylinder attached after the production.SOLUTION: In a thrust force magnifying device 1, a retraction stopper 361 which contacts with a hydraulic chamber 8 side end surface of an input side lid 3 is attached to a tip of an input rod 101 as retraction restricting means for restricting retraction of the input rod 101 of an air cylinder 100 attached after production. The retraction stopper 361 is attached so that a step part (a flat part etc.) of the input rod 101 is stopped at a position located at the hydraulic chamber 8 side relative to an O ring 47 for the input rod 101 in a state that the retraction stopper 361 contacts with the input side lid 3 etc. The structure prevents the step part from interfering with the O ring 47 by advancement or retraction of the input rod 101.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a thrust magnification device, and more particularly to a thrust magnification device that outputs an input pressure as an amplified thrust. [Background technology]

[0002] Fluid pressure cylinders that use fluids such as air (gas) and oil (liquid) are used in a wide range of industrial fields. These fluid pressure cylinders can serve as the driving force for various mechanical operations, such as driving a press or an actuator, by generating thrust on a piston inside the cylinder using fluid pressure. One such fluid pressure cylinder is an air-hydro cylinder that converts air pressure into hydraulic pressure inside the cylinder (Patent Document 1). In this air-hydro cylinder, an air cylinder (input side) and a hydraulic cylinder (output side) that amplifies thrust are integrated into a common cylinder, with an air piston that is driven by air being placed on the input side of the cylinder, and a hydraulic piston that is driven using the output of the air piston as input and an output rod being placed on the output side.

[0003] For such air-hydro cylinders, a thrust magnifying device has been proposed that makes it possible to replace various types of air cylinders by separating and making the output hydraulic cylinder section (thrust magnifying mechanism section) independent from the input air cylinder section (Patent Document 2). In this thrust magnification device, through holes are provided in the cylinder wall that constitutes the hydraulic chamber to match the diameter of the output rods (called input rods because they input thrust into the thrust magnification device) of the various actuators that will be added later, and the thrust magnification mechanism is activated by inserting the input rod of an air cylinder or the like into this hole.

[0004] FIG. 10 shows a general-purpose air cylinder 100 that is retrofitted to a thrust magnification device, with FIGS. 10(a) to (d) showing a female-thread type air cylinder and FIG. 10(e) showing a male-thread type air cylinder 100. As shown in Fig. 10, an air cylinder 100 has an input rod 101 that moves forward and backward in the axial direction by air supply from intake and exhaust holes 102 and 103. A female thread 152 (see Figs. 10(b) and (d)) or a male thread 154 (see Fig. 10(e)) for attaching various members is formed at the tip of this input rod 101. In addition, a spanner engagement portion (hereinafter referred to as a flat cut) 151 consisting of two faces cut parallel to the side surface of the cylindrical portion is formed, which is necessary when attaching members to the female thread 152 or male thread 154 at the tip of the input rod 101. In this way, the tip of the input rod 101 of a typical air cylinder 100 has a stepped portion due to flat cutting, and a stepped portion due to a portion where a male thread is formed and a portion where a male thread is not formed.

[0005] For this reason, if a general air cylinder or the like is retrofitted to the thrust magnification device, when the air cylinder is installed or the input piston is operated, the O-ring for the hydraulic seal provided in the through hole for the input rod provided in the thrust magnification device may interfere with the stepped portion formed on the input rod, potentially damaging the O-ring. In addition, it is possible to avoid damage to the O-ring by using an air cylinder with an input rod that is cylindrical along its entire length, but this requires a special order.

[0006] Furthermore, when the input actuator is an air cylinder, its stroke is standardized in stages, for example, from 10 mm to 50 mm in 10 mm increments, from 50 mm to 100 mm in 25 mm increments, etc. For this reason, if a stroke between stages is required, it is necessary to either custom-make it, or use an air cylinder with a short standard stroke and change the stroke specifications that can be output by the thrust magnification device. Most air cylinders generally have two-point operation, forward and backward, but the thrust magnification device described in Patent Document 2 does not allow the stroke on the forward side of the air cylinder to be adjusted, i.e., it does not allow the stopping position of the forward end of the input rod to be adjusted, so it was not possible to change the air cylinder to one with a longer stroke than the original design specifications. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4895342 [Patent Document 2] JP 2020-076495 A Summary of the Invention [Problem to be solved by the invention]

[0008] A first object of the present invention is to provide a thrust magnifying device that is capable of adjusting the stroke range of an input rod in an input actuator that is attached later. A second object of the present invention is to prevent interference between a seal means for sealing a fluid in the thrust magnification device and a step portion of an input rod in an input actuator. [Means for solving the problem]

[0009] (1) In the invention described in claim 1, there is provided a thrust magnifying device which amplifies and outputs a thrust input from an input actuator by connecting a force actuator to the thrust magnifying device, the thrust magnifying device including a cylinder having an axial through hole formed in a thrust direction, a fluid chamber formed in the cylinder, a piston portion disposed in the axial through hole, one side surface of which constitutes a part of an inner wall surface of the fluid chamber and which moves in the thrust direction, a fluid piston having an output rod connected to the piston portion and which outputs the magnified thrust, an output side lid portion connected to one end of the cylinder and having a through hole formed therein through which the output rod moves in the thrust direction, an input lid portion disposed at an open end of a through hole formed in the cylinder and communicating with the fluid chamber, and having an opening through which the input rod of the input actuator is inserted, input fixing means for fixing the input actuator with the input rod inserted in the opening, sealing means disposed on an inner peripheral surface of the opening and for sealing between the opening and the input rod, and a fluid piston having an output rod connected to the fluid piston and an output rod connected to the output rod In the backward direction Restricting the range of motion retreat The present invention provides a thrust magnification device comprising: (2) In the invention described in claim 2, retreat the restricting means restricts the movement of the input rod in the rearward direction such that a step end position of a step formed at the tip of the input rod, the step end position being farthest from the tip of the input rod, stops at a position closer to the fluid chamber than a shield end position of the shield means closest to the fluid chamber. (3) In the invention described in claim 3, retreat The thrust magnification device according to claim 2, wherein the restriction means includes a rearward stopper that is formed so as to have an outer diameter larger than an inner diameter of the opening and is disposed at the tip of the input rod in a state where the interference avoidance condition "step distance D1<ring distance R1" is satisfied. Here, the distance from the step end position to the abutment surface P between the rearward stopper and the input lid portion is the step distance D1, and the distance from the shield end position to the abutment surface P is the ring distance R1. (4) In the invention described in claim 4, before The forward movement of the input rod is restricted so that the input rod stops at a position before an inner surface of the cylinder, which faces a tip end surface of the input rod. Equipped with forward restriction means The present invention provides a thrust magnification device as claimed in claim 1, claim 2, or claim 3. (5) In the invention described in claim 5, before an adjustment pin that penetrates a side surface of the cylinder that faces the tip surface of the input rod and has a tip on one end side that abuts against the input rod to restrict forward movement of the input rod; Equipped with forward limiting means, The present invention provides a thrust magnification device according to any one of claims 1 to 4. (6) In the invention described in claim 6, forwardThe thrust magnification device according to claim 5, characterized in that the regulating means has an adjustment block fixed to an outer wall surface of the cylinder, the adjustment pin has a male thread formed on the other end side, and the adjustment block has a through hole through which the adjustment pin is inserted and which has a female thread formed therein and which screws into the male thread of the adjustment pin. (7) The invention described in claim 7 provides a thrust magnification device described in any one of claims 1 to 6, characterized in that the cylinder has a side through hole formed in a side wall thereof, and the input lid portion is arranged at an open end of the side through hole. (8) The invention described in claim 8 provides a thrust magnification device according to any one of claims 1 to 3, characterized in that the input lid portion is disposed at an open end on the other end side of the axial through hole. (9) In a ninth aspect of the present invention, there is provided a thrust magnification device according to any one of the first to eighth aspects, wherein a surface of the piston portion to which the output rod is not connected constitutes a part of a partition wall of the fluid chamber. (10) The invention described in claim 10 provides a thrust magnification device described in any one of claims 1 to 8, characterized in that a surface of the piston portion on the side to which the output rod is connected constitutes a part of a partition wall of the fluid chamber, and the output rod acts in a pulling direction to cause the magnified thrust to act. (11) The invention described in claim 11 provides the thrust magnification device described in claim 10, characterized in that the input lid portion is disposed at a position where an extension of a center line of the opening is farther away from a center line of the output rod than a distance obtained by adding a radius of the opening and a radius of the output rod. Effect of the Invention

[0010] According to the present invention, since the restricting means for restricting the movable range of the input rod within the fluid chamber is provided, it is possible to provide a thrust magnifying device that can adjust the stroke range of the input rod in an input actuator that is attached later. Furthermore, according to the invention described in claim 2, the movement of the input rod in the rearward direction is restricted so that the step end position of the step portion formed on the input rod stops at a position closer to the fluid chamber than the shield end position of the shield means, thereby making it possible to avoid interference between the sealing means and the step portion of the input rod. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram of a thrust magnification device equipped with an air cylinder. [Diagram 2] 11 is an explanatory diagram of an interference avoidance condition for avoiding interference between a step portion of an input rod and an O-ring. FIG. [Diagram 3] 5A to 5C are explanatory diagrams showing a procedure for retrofitting an air cylinder to the thrust magnification device of the first embodiment. [Figure 4] 5A to 5C are diagrams illustrating the operation of the thrust magnification device according to the first embodiment. [Diagram 5] 10 is an explanatory diagram of a thrust magnification device according to a second embodiment. FIG. [Figure 6] 13 is an explanatory diagram of a thrust magnification device according to a third embodiment. FIG. [Figure 7] 13 is an explanatory diagram of a thrust magnification device according to a fourth embodiment. FIG. [Figure 8] 13 is an explanatory diagram of a thrust magnification device according to a fifth embodiment. FIG. [Figure 9] 13 is an explanatory diagram of a thrust magnification device according to a sixth embodiment. FIG. [Figure 10] 10 is an explanatory diagram of an air cylinder that is attached to the thrust magnification device. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (1) Overview of the embodiment The thrust magnification device 1 of this embodiment has an input function for inputting a thrust that is the source of the output thrust, and a thrust magnification function for magnifying the input thrust as a fluid pressure utilizing Pascal's principle and outputting it, and is formed by separating and independently forming a part that constitutes the thrust magnification function from a so-called air-hydro cylinder. The thrust magnification device 1 does not operate independently as it does not have an input function within itself. It can be operated by assembling (retrofitting) various input side actuators directly or via an adapter to obtain the thrust (input) to be magnified.

[0013] Specifically, an input port (through hole) of a fluid chamber (hydraulic chamber 8) that is adapted to the rod diameter of various actuators on the input side is provided on the input side of the thrust magnification device 1, and the thrust magnification mechanism operates by inserting the rod of the input side actuator (input rod 101, etc.) into the input port. The input actuator mounting section of the thrust magnification device 1 is configured so that the parts can be changed to suit the fixing method and rod shape of various actuators. By changing the lid adapter 4 of the input lid 3, the cross-sectional area of ​​the input rod can be changed, and the thrust magnification ratio can be freely changed. In addition, by changing the input stroke of the input actuator, the stroke of the output rod can be changed. According to the thrust magnification device 1, since it is separated and independent from the input side actuator, various types of cylinders that are commonly used can be easily attached and replaced.

[0014] The thrust magnification device 1 of this embodiment is provided with a restricting means for restricting the movable range of the input rod of the input actuator, which is attached later, when the input rod moves forward and backward. As an example of this regulating means, a retraction stopper 361 or a retraction stopper 365 that abuts against the end face of the hydraulic chamber 8 side of the input side lid 3 (lid adapter 4 if there is a lid adapter 4) is attached to the female thread 152 or male thread 154 of the input rod 101 as a retraction regulating means for regulating the retraction of the input rod. The backward stoppers 361, 365 are attached so that when in contact with the end face of the input side cover 3 or the like on the hydraulic chamber 8 side, the stepped portion (flat chamfer 151, etc.) of the input rod 101 stops at a position closer to the hydraulic chamber 8 than the O-ring 47 for the input rod 101. This prevents the stepped portion from interfering with the O-ring 47 when the input rod 101 moves forward or backward.

[0015] As another example of a regulating means, an advancement adjustment unit 370 having an adjustment pin 373 that abuts against the tip of the input rod 101 (the tip of the input rod 101 in the case of a male thread type, or the tip of a locking bolt 362 that fixes the backward stopper 361 in the case of a female thread type) is provided in the cylinder 2 as an advancement regulating means for regulating the forward movement of the input rod 101. The position of the tip of the adjustment pin 373 can be adjusted in the front-rear direction within the hydraulic chamber 8. The position of the tip of the adjustment pin 373 can be adjusted according to the stroke of the attached air cylinder 100. Therefore, it is possible to replace it with another air cylinder 100 having a different stroke. The position adjustment of the adjustment pin 373 by the advance adjustment unit 370 can be performed from outside the device even after an input side actuator such as an air cylinder or an electric cylinder is incorporated. As the restricting means for restricting the stroke of the input rod 101, at least one of a retraction restricting means for restricting the movement in the retraction direction and an advancement restricting means for restricting the movement in the advancement direction may be provided.

[0016] (2) Details of the First Embodiment FIG. 1 shows the state in which an air cylinder 100 serving as an input actuator is attached to the thrust magnification device 1 in the first embodiment, where (a) shows a cross section (AA cross section) in the thrust direction (direction of the center line), (b) shows the BB cross section from above, and (c) shows the CC cross section from the right side. As shown in FIG. 1, the thrust magnification device 1 includes a cylinder 2 that forms a part (circumferential surface) of a hydraulic chamber 8. The cylinder 2 is formed in a rectangular parallelepiped shape that is long in the vertical direction (longitudinal direction) of FIG. 1(a), and has an axial through hole that penetrates in the vertical direction and partially forms a hydraulic chamber 8. Furthermore, side through holes communicating with the hydraulic chamber 8 are formed on three of the four side surfaces of the cylinder 2. Of the four side surfaces of the cylinder 2, the three side surfaces on which the side through holes are formed have the same thickness, and are formed thicker than the surfaces on which the side through holes are not formed. The axial through hole of the cylinder 2 and the side through holes on the three sides are formed to have the same diameter, so that an air cylinder 100 can be attached to any of the through holes, as described below.

[0017] The side through-holes are also used when connecting multiple thrust magnification devices 1 with an adapter. That is, by fixing an adapter with a communication through-hole formed in the center to the side surfaces of two thrust magnification devices 1, the hydraulic chambers 8 of both thrust magnification devices 1 are connected to each other. By connecting a plurality of thrust magnification devices 1 via adapters in this manner, a plurality of air cylinders 100 can be attached. Then, depending on the number of air cylinders 100 to be driven, that is, the number of input rods 101 moving forward into the hydraulic chambers 8, the stroke of the output rod 72 of each thrust magnification device 1 can be changed in stages.

[0018] As shown in Figures 1(a) and (c), an upper cover 3a is fixed to the upper part of the axial through hole of the cylinder 2. Furthermore, of the three side through holes formed in the side of the cylinder 2, side covers 3b and 3c are fixed to two opposing side through holes as shown in Figures 1(b) and (c). The top cover 3a and the side covers 3b and 3c are formed in the same shape, and have protrusions formed therein with substantially the same diameter as the axial through-hole and side through-hole of the cylinder 2. A groove is formed over the entire outer periphery of each protrusion, and an O-ring 39 is disposed therein. By inserting the convex portions of the upper lid 3a and the side lids 3b and 3c into the through-holes of the cylinder 2, each O-ring 39 is pressed against the inner surface of the through-hole, thereby sealing the oil in the hydraulic chamber 8 of the cylinder 2. The top cover 3a and the side covers 3b, 3c are each fixed to the cylinder 2 by eight pressing bolts 33a, 33b, 33c, similar to the input side cover 3 shown in FIG. 1(c) and described later.

[0019] In addition, a side input through hole 31 (see Figure 3 (b)) is formed on the remaining side of the cylinder 2, i.e., the side opposite to the side on which the side through hole is not formed, and a part of the input side cover 3 is inserted and fixed into this side input through hole 31. A lid adapter 4 that can be replaced depending on the input actuator to be used later is attached to the center of the input side lid 3. The input side lid 3 and the lid adapter 4 function as an input lid section. On the other hand, an output side lid 5 is fixed to the lower side in the longitudinal direction of the cylinder 2, that is, to the end opposite to the upper lid 3a, and a stopper lid 6 is attached to the center of this output side lid 5.

[0020] An abutment wall 4w is formed near the center of the axial through hole of the cylinder 2, separating the upper cover 3a side from the output side cover 5 side. As shown in FIG. 1(b), the contact wall 4w is formed in a semicircular arc shape protruding inwardly of the cylinder 2, and is formed at two locations (on the same plane) on the air cylinder 100 side and the opposite side. The abutment wall 4w has a flat plate portion 4w1 whose one end side extends from the cylinder 2, and a curved surface portion 4w2 which extends further from the flat plate portion 4w1 and gradually becomes thinner toward the center of the axial through hole. 1(a), the curved surface portion 4w2 is a curved surface formed by the formation of a side through hole penetrating from the side cover 3b side to the side cover 3c side, and coincides with the inner peripheral surface J1 of the side through hole. By forming the side through hole, the space between the two opposing abutment walls 4w (the central portion) is cut. In FIG. 1(b), the reference symbol J2 denotes the inner peripheral surface of the axial through hole.

[0021] The abutment wall 4w is formed, for example, as follows: After forming a small-diameter through hole whose inner circumferential surface is represented by J3 (FIG. 1(b)) in the axial direction of the cylinder 2, an axial through hole whose inner circumferential surface is represented by J2 is formed from both the top and bottom directions, leaving a width corresponding to the thickness of the flat plate portion 4w1. This forms a flange-shaped portion that protrudes inwardly of the cylinder 2, has a width from the inner circumferential surface J2 to the inner circumferential surface J3, and includes the flat plate portion 4w1. Furthermore, by forming a side through hole represented by an inner circumferential surface J1 (FIG. 1(a)), the portion between the two contact walls 4w in the flange-shaped portion is cut and a curved surface portion 4w2 is formed. The order in which the through holes are formed is merely an example, and the through holes may be formed in a different order.

[0022] A hydraulic piston 7 (fluid piston) is disposed in the axial through hole of the cylinder 2, closer to the output side cover 5 than the contact wall 4w. The abutment wall 4w has a function of determining the position of the piston portion 71 of the hydraulic piston 7 in the initial state by being abutted against the abutment wall 4w.

[0023] The components constituting the thrust magnification device 1 of this embodiment (excluding specific components such as an O-ring and a sliding assist ring) are made of metal such as aluminum, stainless steel, or iron. The size of the thrust magnification device 1 is, by way of example, about 70 mm in width of the side wall, about 120 mm in length in the vertical direction (when the hydraulic piston 7 is in the initial state), and about 5 mm in stroke length of the output rod 72, but it may be larger or smaller than these. The cylinder 2, input side lid 3, lid adapter 4, output side lid 5, stopper lid 6, and hydraulic piston 7 will each be described below.

[0024] The cylinder 2 has eight bolt holes for clamping bolts 54 that secure the output side lid 5 and eight bolt holes for clamping bolts 33a that secure the upper lid 3a at the output side (lower side) and upper open end, respectively. In addition, on each of the three sides of cylinder 2 where the side through holes are formed, there are eight bolt holes for clamping bolts 33b that secure side cover 3b, eight bolt holes for clamping bolts 33c that secure side cover 3c, and eight bolt holes 26 for clamping bolts 33 that secure cover portion 3, which will be described later. The bolt holes for the pressing bolts 33a, 33b, and 33c, which are formed in eight locations, and the bolt hole 26 for the pressing bolt 33 are formed in the same positional relationship (see FIG. 1(c)). Therefore, the attachment positions of the upper lid 3a, the side lids 3b and 3c, and the lid portion 3 can be changed to any position. In this embodiment, the lid portion 3 is attached to one location, but it may be disposed in two, three, or four locations. In this case, the upper lid 3a or the side lids 3b and 3c are attached to the other locations where the lid portion 3 is not attached.

[0025] An oil supply port 21 is formed on the side surface of the cylinder 2 on which the side surface through hole is not formed, at a position above the contact wall 4w. The oil filler port 21 is a through hole for supplying a fluid such as oil into the hydraulic chamber 8 described below, and is adapted to be closed by an oil filler plug 22. Although one is shown in the drawing, two oil filler ports 21 and two oil filler plugs 22 are provided on the same circumference of the cylinder 2, and one of them is used to supply oil into the hydraulic chamber 8, while the other is used for bleeding air. Note that a pressure sensor may be attached to one of the oil filler ports 21 so that the oil pressure in the hydraulic chamber 8 can be detected.

[0026] The hydraulic chamber 8 is composed of hydraulic chambers 8a, 8b, and 8c which are in communication with each other, and function as a fluid chamber. The hydraulic chamber 8a corresponds to a bottomed hollow portion 73 (recess) formed in the piston portion 71 of the hydraulic piston 7 and the output rod 72. The hydraulic chamber 8b corresponds to a space on the upper cover 3a side of the end face of the piston portion 71 opposite to the output rod 72 in the axial through hole of the cylinder 2. The hydraulic chamber 8c corresponds to a part of a side through hole formed for mounting the input side cover 3. In each of the following embodiments, each of the interconnected hydraulic chambers 8a, 8b, 8c, etc. will be referred to as hydraulic chamber 8 when referring to the entire hydraulic chamber, and will be described with suffixes such as a, b, c, etc. added to hydraulic chamber 8 when referring to an individual hydraulic chamber.

[0027] A through hole for the intake and exhaust port 24 is formed near the end face portion below the contact wall 4w of the cylinder 2. In this embodiment, the intake and exhaust port 24 is formed on the same side surface as the fuel filler port 21, but it is also possible to form it on another side surface. The intake and exhaust port 24 is a through hole for intake and exhaust of air in the air chamber 9, which will be described later. The air chamber 9 and the intake and exhaust port 24 function as a biasing means for applying a force in the input side direction to the fluid piston (hydraulic piston 7). The internal volume of the air chamber 9 increases and decreases as the piston portion 71 moves in the axial direction, and gas (air) is sucked in and exhausted through the intake and exhaust port 24 in accordance with this increase and decrease in internal volume. Incidentally, in the other embodiments as well, a silencer may be provided inside the intake and exhaust port 24 to muffle / reduce the intake and exhaust sound of gas.

[0028] The input side cover 3 is formed in a plate shape having a large diameter flange portion and a small diameter portion. The small diameter portion of the input side cover 3 is accommodated in a side input through hole 31 (see FIG. 3(b)) formed in the side surface of the cylinder 2. Through holes 32 are formed in eight locations in the flange portion of the input side lid 3. Then, as shown in FIG. 1(b), eight pressing bolts 33 are inserted through the through holes 32 and screwed into the screw holes 26 of the cylinder 2, thereby fixing the input side lid 3 to the cylinder 2. The flange portion of the input side lid 3 is not circular as shown in Fig. 1(c), but is formed in a square shape with the four corners cut off concentrically. As a result, the flange portion of the input side lid 3 has four flat surfaces on the outer periphery, and the length between the opposing flat surfaces is greater than the diameter of the cylinder 2. This shape is the same as the flange portion of the output side lid 5 described later.

[0029] An adapter through hole for arranging the lid adapter 4 is formed in the center of the input side lid 3. The adapter through hole is formed so that the inner diameter on the hydraulic chamber 8 side (hereinafter referred to as the inner side) is smaller than the contact side (hereinafter referred to as the outer side) of the air cylinder 100 in accordance with the shape of the lid adapter 4, thereby forming a stepped portion, and a screw hole 34 is formed in this stepped portion (on the outer side) toward the inner side. As shown in Figures 1(a) and 1(c), four screw holes 35 are formed on the outer end surface of the lid adapter 4. These screw holes 35 do not appear in the cross section of Figure 1(a), and are therefore indicated by dotted lines in the figure. These screw holes 35 function as input fixing means for fixing an input cylinder device, such as an air cylinder 100, to the thrust magnification device 1 with a holding bolt 109. In addition, an outer circumferential groove is formed around the entire outer circumferential surface of the small diameter portion of the input side cover 3 that is housed in the cylinder 2, and an O-ring 39 is disposed in this outer circumferential groove. The O-ring 39 seals the oil in the hydraulic chamber 8, which will be described later.

[0030] A lid adapter 4 is disposed in the adapter through hole of the input side lid 3 , and the lid adapter 4 is fixed to the input side lid 3 with a pressing bolt 44 . The lid adapter 4 is formed in a plate shape having a large diameter flange portion and a small diameter portion, and has a through hole (input portion) for an input rod formed in the center. The through hole for the input rod formed in the lid adapter 4 functions as an opening in this embodiment. The through hole for the input rod of the lid adapter 4 is formed with an inner diameter on the inner side larger than the inner diameter on the outer side, so that the inner diameter is formed in two stages. A guide bush 42 with a thickness equal to the difference between the inner diameters on the inner side and the outer side is arranged on the inner side. The outer diameter of the guide bush 42 is the same as the inner diameter of the inner surface of the input rod through hole, and the inner diameter of the guide bush 42 is the same as the inner diameter (narrower diameter) of the outer surface of the input rod through hole. However, the outer diameter of the guide bush 42 is formed larger by an allowance (size tolerance range) for press-fitting into the input rod through hole. The inner diameter of the guide bush 42 is larger than the outer diameter of the input rod 101 to be inserted, and is smaller than the inner diameter of the outer surface of the input rod through hole within the size tolerance range so that the input rod 101 does not contact the lid adapter 4. The axial length of the guide bush 42 is formed such that the inner end face is shorter than the length to the inner end face of the lid adapter 4 by the size tolerance. The guide bush 42 is a guide member that receives, on its inner circumferential surface, the input rods of various cylinders attached to the thrust magnification device 1 and guides the movement of the input rod 101 in the front-rear direction (axial direction).

[0031] The flange portion (large diameter portion) of the lid adapter 4 has four through holes 43 formed therein corresponding to the four clamp bolts 44 shown in Fig. 1(c). The clamp bolts 44 are inserted through the through holes 43 and screwed into the screw holes 34 of the input side lid 3, thereby fixing the lid adapter 4 to the input side lid 3. The lid adapter 4 is appropriately replaced according to the size of the air cylinder 100 to be attached later, in particular the size of the input rod 101 to be inserted into the input rod through hole. The inner diameters of the input rod through hole and the guide bush 42 of the replaced lid adapter 4, and the size of the O-ring 47 described later are appropriately selected according to the diameter of the input rod 101. The lid adapter 4 can be replaced by removing the retaining bolt 44 . According to this embodiment, by providing a lid adapter 4 corresponding to the input rod 101 of the air cylinder 100 in addition to the input side lid 3, it is possible to easily replace the input side actuator with a different type, such as a different size air cylinder 100 or an electric cylinder, while keeping the hydraulic piston 7 housed inside. In this embodiment, the input side lid 3 and the lid adapter 4 function as the input lid part, but instead of making the input side lid 3 and the lid adapter 4 separate, an integrally formed input side lid 3 may be used, removed with the retaining bolt 33, and replaced with an input side lid 3 that matches the diameter of the input rod of the cylinder device. In this case, the integrally formed input side lid 3 functions as the input lid part.

[0032] An inner circumferential groove is formed around the entire inner circumferential surface on the outer side of the input rod through hole in the lid adapter 4, and an O-ring 47 (see Figure 1 (a)) that functions as a sealing means for sealing the oil in the hydraulic chamber 8 is disposed in this inner circumferential groove. In addition, an outer circumferential groove is formed around the entire outer circumferential surface of the small diameter portion of the lid adapter 4, and an O-ring 49 (see Figure 1 (a)) is disposed in this outer circumferential groove to seal the oil in the hydraulic chamber 8.

[0033] As shown in Fig. 1(a), an input rod 101 of a female-threaded air cylinder 100 (see Fig. 10(a)) to be attached later is inserted into the input rod through hole of the lid adapter 4. The tip of this input rod 101 is formed with a step portion such as a flat chamfer 151 (spanner hook portion) of the input rod 101. In this embodiment, in order to prevent the step portion of the input rod 101 from interfering with the O-ring 47 of the lid adapter 4, a retraction stopper 361, which functions as a retraction restriction means, is fixed to the tip of the input rod 101 with a locking bolt 362. The outer diameter of the rearward stopper 361 is larger than the inner diameter (inner surface side) of the input rod through hole in the lid adapter 4, and is smaller than the inner diameter on the hydraulic chamber side of the side input through hole 31 (see Figure 3) formed on the side of the cylinder 2. As a result, when the input rod 101 of the air cylinder 100 is retracted, the retraction stopper 361 abuts against the inner surface of the lid adapter 4, thereby avoiding interference between the step portion (flat edge 151) of the input rod 101 and the O-ring 47. The conditions required to avoid interference between the step portion (flat cut 151) of the input rod 101 and the O-ring 47 will be described later.

[0034] On the other hand, an output side cover 5 is disposed at the lower end of the cylinder 2 in the longitudinal direction. The output-side cover 5 is formed in a plate shape having a small diameter portion and a large diameter flange portion. The small diameter portion of the output-side cover 5 is housed in the cylinder 2, and the end face on the inner surface side (hydraulic chamber 8 side) of the flange portion abuts against the open end of the cylinder 2. An outer circumferential groove is formed around the entire outer circumferential surface of the small diameter portion of the output side cover 5, and an O-ring 59 that seals the air in the air chamber 9 is disposed in this outer circumferential groove (see FIG. 1(a)). The flange portion of the output-side lid 5 has six through holes for the presser bolts 54. The six presser bolts 54 are inserted through the through holes and screwed into screw holes formed in the end face of the cylinder 2, thereby fixing the output-side lid 5 to the cylinder 2. The flange portion of the output side lid 5 is formed in a rectangular shape with the four corners cut out in concentric circles, similar to the input side lid 3 (see FIG. 1(c)).

[0035] An output through hole in which the stopper cover 6 is disposed is formed in the center of the output side cover 5. The inner peripheral surface of the output through hole of the output side cover 5 is formed with a small inner diameter portion, a medium inner diameter portion, and a large inner diameter portion from the hydraulic chamber 8 side toward the outer surface side. The output side cover 5 and the stopper cover 6 function as the output side cover portion. The step (outer surface) formed by the medium inner diameter portion and the large inner diameter portion of the output side lid 5 has six screw holes formed toward the hydraulic chamber 8. These screw holes are for fixing the retaining lid 6, which will be described later, to the output side lid 5 with a pressing bolt 63.

[0036] A guide bush 51 having a thickness equal to the difference between the small inner diameter section and the medium inner diameter section is disposed in the medium inner diameter section of the output through hole of the output side cover 5. The axial length of the guide bush 51 is the same as the axial length of the medium inner diameter section. The outer diameter and inner diameter of the guide bush 51 are the same as the inner diameter of the medium inner diameter section and the inner diameter of the small inner diameter section, respectively, of the output through hole. However, as with the guide bush 42, the outer diameter and inner diameter of the guide bush 51 are formed larger within the range of the dimensional tolerance by an amount corresponding to the press-fit, and the inner diameter is formed smaller within the range of the dimensional tolerance so that the inserted output rod 72 does not come into contact with anything other than the guide bush 51. In addition, the axial length of the guide bush 51 is also formed shorter within the range of the dimensional tolerance than that of the medium inner diameter portion. The guide bush 51 is a guide member that receives, on its inner circumferential surface, an output rod 72 of the hydraulic piston 7 disposed in the cylinder 2, and guides the movement of the output rod 72 in the front-rear direction (axial direction).

[0037] One hole 55 and six holes 57a are formed at positions that do not interfere with each other on the outside of the medium inner diameter portion of the output through hole of the output side cover 5. The numbers of holes 55 and holes 57 can be set arbitrarily. Inside the hole 55, a rotation-preventing pin 75 slides in the same direction as the hydraulic piston 7 as the hydraulic piston 7 moves, as described below. One end of the coil spring 57 is inserted and fixed inside the hole 57a. The other end of the coil spring 57 (biasing means) abuts against the outer end face of the piston portion 71 (the side opposite to the hydraulic chamber 8). Additionally, screw holes 56 are formed at six concentric positions on the outer end surface of the output-side cover 5. The screw holes 56 are for attaching various members to the output side of the thrust magnification device 1.

[0038] A stopper cover 6 is disposed on the large inner diameter portion of the output through hole in the output side cover 5 for fixing a guide bush 51 disposed on the medium inner diameter portion. A rod through hole, through which the output rod 72 is inserted, is formed in the center of the stopper cover 6. An inner peripheral groove is formed around the entire circumference of the inner surface of this rod through hole, and a dust seal 65 is disposed in this inner peripheral groove. The dust seal 65 prevents dust, foreign matter, and the like that adheres to the output rod 72 from entering the inside of the thrust magnification device 1 from the outside when the output rod 72 slides. Six through holes are formed on the outside of this rod through hole on a concentric circle, and six pressure bolts 63 are inserted through each of these through holes and screwed into screw holes formed in the output side lid 5, thereby fixing the retaining lid 6 to the output side lid 5. In this embodiment, the retaining cover 6 and the output side cover 5 are formed separately and fixed together with a pressure bolt 63, but it is also possible to form the output side cover 5 and the retaining cover 6 as a single unit.

[0039] The hydraulic piston 7 includes a piston portion 71 and an output rod 72 extending from the center of the piston portion 71 toward the output side (the side opposite to the hydraulic chamber 8). The piston portion 71 is disposed inside the cylinder 2, and together with the cylinder 2, the surface on the hydraulic chamber 8 side forms part of the inner wall of the hydraulic chamber 8, and the surface on the output side forms part of the air chamber 9. An outer circumferential groove is formed around the entire outer circumferential surface of the piston portion 71, and an O-ring 79 that seals between the hydraulic chamber 8 and the air chamber 9 is disposed in this outer circumferential groove.

[0040] The output side end face of the piston portion 71 is formed with a pin hole 74 and a pin hole 76 at positions corresponding to the holes 55 and 57 a of the output side cover 5 . One end of a rotation-preventing pin 75 is fixed by press fitting into the pin hole 74, and the other end of the rotation-preventing pin 75 is slidably inserted into the output-side cover 5. The rotation-preventing pin 75 prevents the piston portion 71 from rotating in conjunction with its movement. One end of a guide pin 77 is fixed in the pin hole 76 by press fitting, and the other end of the guide pin 77 is inserted into the coil spring 57 to guide the expansion and contraction of the coil spring 57. In this embodiment, six coil springs 57 are arranged circumferentially, but only one coil spring may be used. In this case, a coil spring having an inner diameter larger than the outer diameter of the output rod 72 is used, the output rod 72 is inserted into the inner diameter of the coil spring, and one end of the coil spring is in contact with the piston portion 71 and the other end of the coil spring is in contact with the output-side cover 5 via an appropriate positioning groove or the like. The anti-rotation pin 75 and the coil spring 57 are an example of an anti-rotation member.

[0041] A bottomed hollow portion 73 that does not axially penetrate from the hydraulic chamber 8b side is formed in the center of the hydraulic piston 7. The inside of this hollow portion 73 also constitutes a part of the hydraulic chamber 8 (hydraulic chamber 8a). A bolt hole 72a is formed on the end side of the output rod 72 of the hydraulic piston 7 from the end face toward the hydraulic chamber 8. This bolt hole 72a is for attaching various tools such as a punch for a punching die used in press working or the like.

[0042] Next, interference avoidance conditions for avoiding interference between the step portion (flat cut 151) of the input rod 101 and the O-ring 47 will be described. The interference avoidance condition is a condition for restricting the backward movement of the input rod 101 so that the step end position, which is the furthest from the tip of the input rod 101 in the step portion (flat chamfer 151, etc.) formed at the tip of the input rod 101, stops at a position closer to the hydraulic chamber 8 than the position (shield end position) closest to the hydraulic chamber 8 (fluid chamber) on the O-ring 47 (shield means).

[0043] Fig. 2 is an explanatory diagram of the interference avoidance conditions. In Fig. 2, the cylinder 2 and the input side lid 3 are omitted, and the input rod 101 to which the rearward stopper 361 is fixed by the locking bolt 362 and the lid adapter 4 are shown in an enlarged scale. As shown in FIG. 2, the distance from the position closest to the body of the air cylinder 100 at the step portion such as the flat cut 151 (the step end position farthest from the tip) to the abutment surface P between the rearward stopper 361 and the lid adapter 4 is defined as step distance D1, and the distance to the abutment surface Q between the rearward stopper 361 and the tip of the input rod 101 is defined as step distance D2. The distance from the position of the O-ring 47 closest to the rear stopper 361 (shield end position) to the abutment surface P is defined as ring distance R1, and the distance from the position to the abutment surface Q is defined as ring distance R2.

[0044] The condition for avoiding interference between the step portion of the input rod 101 and the O-ring 47 is expressed by the following formula (1). Step difference D1 < Ring distance R1 …(1)

[0045] In the case of the lid adapter 4 and the input rod 101 shown in FIGS. 1 and 2(a), since the step difference D2 is smaller than the ring distance R2 (D2 < R2), even if the contact surface P and the contact surface Q are the same surface, the interference avoidance condition of the above formula (1) is satisfied. Therefore, the retreat stopper 361 is formed such that the end surface on the side of the air cylinder 100 is flat, so that the contact surface P and the contact surface Q are the same surface.

[0046] On the other hand, as shown in FIG. 2(b), when the step difference D2 is greater than or equal to the ring distance R2 (D2 ≥ R2), if the retreat stopper 361 is made flat and the contact surface P and the contact surface Q are the same surface, the interference avoidance condition (D1 = D2 < R1 = R2) is not satisfied, so that the stepped portion (flattening 151) interferes with the O-ring 47. Therefore, when the step difference D2 is greater than or equal to the ring distance R2 (D2 ≥ R2), as shown in FIG. 2(c), the interference avoidance condition is satisfied by using the retreat stopper 361 in which a concave portion 363 having an inner diameter larger than the outer diameter of the input rod 101 is formed at the center. That is, the contact surface P and the contact surface Q are not the same surface, and the position of the contact surface Q with respect to the contact surface P is moved forward (to the stop bolt 362 / hydraulic chamber 8) side to a position where the step difference D1 < ring distance R1, so as to satisfy the interference avoidance condition. Specifically, the concave portion 363 formed in the retreat stopper 361 is formed deeper than the distance obtained by subtracting the ring distance R1 from the step difference D2 to the contact surface Q (the tip surface of the input rod 101) to the contact surface P (the tip surface of the lid adapter 4) (= D2 - R1).

[0047] FIG. 3 is an explanatory diagram showing the procedure for attaching the air cylinder 100 to the thrust enlarging device 1. First, the input side lid 3 in a state where the lid adapter 4 is fixed at the center is removed from the cylinder 2 from the thrust enlarging device 1. 3(a), the input rod 101 of the air cylinder 100 to be attached later is inserted into the input rod through hole of the lid adapter 4. In this state, the press bolt 109, which has passed through the air cylinder 100, is screwed into the screw hole 35 of the lid adapter 4, thereby fixing the air cylinder 100 to the lid adapter 4.

[0048] Next, in a state where the tip of the input rod 101 advances forward beyond the end face of the lid adapter 4, the locking bolt 362 passing through the retraction stopper 361 is screwed into the female thread 152 to fix the retraction stopper 361 to the tip of the input rod 101. As a result, the end face of the retraction stopper 361 on the air cylinder 100 side and the tip face of the input rod 101 come into contact with each other to form an abutment surface P.

[0049] Next, as shown in FIG. 3(b), the small diameter portion of the lid adapter 4, which fixes the air cylinder 100 to the input side lid 3, is inserted into the side input through hole 31 of the cylinder 2, and the retaining bolt 33 is screwed into the screw hole 26 on the side of the cylinder 2, thereby completing the retrofitting of the air cylinder 100. Next, after the air cylinder 100 is attached, the oil filler plug 22 is removed from the cylinder 2 and oil is filled into the hydraulic chamber 8 as shown in FIG. 3(c). In the thrust magnification device 1 of this embodiment, the fluid used in the part that outputs the amplified fluid pressure (thrust) is an oil such as hydraulic oil, which is an easily available incompressible fluid. However, the fluid used may also be a gas, liquid, or gel-like substance that has fluidity. In this case, the hydraulic chamber 8 is filled with the appropriate fluid. In each of the drawings from FIG. 3(c) onwards, the area filled with oil is shown by being filled in order to make it easier to understand the state of hydraulic chamber 8 filled with oil.

[0050] Next, the operation of the thrust magnification device 1 to which the air cylinder 100 is attached will be described. 4A and 4B are diagrams illustrating the operation of the thrust magnification device in the first embodiment, in which (a) shows the initial state of the thrust magnification device 1, and (b) shows the operating state. In FIG. 4, the thrust magnification device 1 is shown in cross section in order to explain the internal state. An air cylinder 100 attached to the thrust magnification device 1 is configured so that an input rod 101 moves in the front-rear direction by air supply and exhaust from intake and exhaust holes 102 and 103. By opening the intake / exhaust hole 102 of the air cylinder 100 and supplying air through the intake / exhaust hole 103, the input rod 101 is brought to its initial state in which it is retracted all the way toward the main body of the air cylinder 100 (to the right side of the drawing), as shown in FIG. 4(a).

[0051] In the initial state of the thrust magnification device 1, the retraction stopper 361 attached to the tip of the input rod 101 abuts against the end face of the lid adapter 4, thereby preventing the input rod 101 from further retracting. As described in FIG 2, the retraction stopper 361 is attached in a state that satisfies the interference avoidance condition expressed by the above formula (1), so that in the initial state, the flat chamfer 151, which is the step portion of the input rod 101, stops closer to the hydraulic chamber 8 than the O-ring 47, thereby avoiding interference.

[0052] When the thrust magnification device 1 is operated, the intake / exhaust port 24 of the thrust magnification device 1 and the intake / exhaust hole 103 of the air cylinder 100 are opened to allow the air inside to escape. In this state, by supplying air from the intake and exhaust port 102, the input rod 101 of the air cylinder 100 advances and enters the hydraulic chamber 8, as shown in Fig. 4(b). This causes the air in the air chamber 9 to escape from the intake and exhaust port 24, and the oil in the hydraulic chamber 8 that was present above the contact wall 4w in the cylinder 2 pushes the piston portion 71 and the output rod 72 toward the output side (downward in the drawing), and the piston portion 71 and the output rod 72 advance by the hydraulic stroke OS. At this time, the oil in the hydraulic chamber 8 pushed out by the input rod 101 flows between the contact wall 4w and the advancing piston portion 71 while pushing the piston portion 71 and the output rod 72. The thrust of the air cylinder 100, that is, the input thrust Fi from the tip of the input rod 101, is amplified (magnified) by hydraulic pressure and output from the tip of the output rod 72 as an amplified thrust Fp.

[0053] Here, assuming that the area of the radial cross-section of the input rod 101 excluding the flat portion 151 is S1, and the area of the piston portion 71 (the area including the bottom surface of the cavity portion 73, which is the same as the radial cross-sectional area of the cylinder 2) is S2, the force received by the piston portion 71 from the oil in the hydraulic chamber 8, that is, the amplified thrust Fp output from the tip of the output rod 72 is as shown in the following equation (2). Fp = (Fi / S1) × S2 = Fi × (S2 / S1) …(2) According to the thrust amplification device 1 of the present embodiment, since S1 < S2, the output rod 72 can output an amplified thrust Fp that is amplified with respect to the input thrust Fi from the input rod 101.

[0054] Note that the operation when returning from the state where the amplified thrust is output from the thrust amplification device 1 (Fig. 4(b)) to the initial state (Fig. 4(a)) is as follows. That is, by setting the intake and exhaust holes 102 to the open state and supplying air from the intake and exhaust holes 103, the input rod 101 of the air cylinder 100 is retracted to the input side. As a result, the volume of the space where the input rod 101 was located in the hydraulic chamber 8 is restored. Since there is no inflow or outflow of fluid from the outside in the hydraulic chamber 8, the oil in the entire hydraulic chamber 8 flows into the restored space portion, and a negative pressure is generated on the piston portion 71 toward the input side. Since the intake and exhaust port 24 is open and the atmospheric pressure is applied to the air chamber 9, the piston portion 71 moves toward the input side. At this time, the urging force of the coil spring 57 assists the movement toward the input side. Here, when returning to the initial state more reliably, air may be supplied from the intake and exhaust holes 103, and air may also be supplied from the intake and exhaust port 24 of the thrust amplification device 1, which was in the open state, to the air chamber 9. Note that the piston portion 71 can be prevented from rotating by the anti-rotation pin 75 with respect to the movement in the output direction and the movement in the input direction. Also, by extending and contracting the coil spring 57 along the guide pin 77, an axial urging force can be applied to the piston portion 71.

[0055] Next, a second embodiment of the thrust amplification device 1 will be described. In the first embodiment described above, a rearward stopper 361 is attached to the tip of the input rod 101 of the retrofit air cylinder 100 so as to satisfy the interference avoidance condition shown in equation (1), thereby preventing the stepped portion (flat edge 151, etc.) of the input rod 101 from interfering with the O-ring 47. That is, in the first embodiment, the rearward movement of the input rod 101 of the retrofitted air cylinder 100 in the forward and backward directions is restricted, thereby satisfying the interference avoidance condition. In contrast, in the thrust magnification device 1 of the second embodiment, in addition to restricting the movement in the backward direction according to the first embodiment, the movement of the input rod 101 in the forward direction is also restricted.

[0056] Fig. 5 shows a state in which an air cylinder 100 is attached to the thrust magnification device 1 according to the second embodiment. Fig. 5(a) shows a cross section in the thrust direction, and Fig. 5(b) shows a horizontal cross section passing through the center line of the input rod 101 as viewed from above. In the thrust magnification device 1 in the second embodiment, an advance adjustment unit 370 (advance restriction means) is provided on the side surface of the cylinder 2, and other parts are similar to those in the first embodiment, so that the description thereof will be omitted as appropriate.

[0057] As shown in FIG. 5, an advance adjustment unit 370 for regulating the advancement of the input rod 101 at a predetermined position is provided on the side surface of the cylinder 2 of the thrust magnification device 1 opposite to the side surface on which the air cylinder 100 is attached. The advance adjustment unit 370 includes an adjustment block 371 and an adjustment pin 373 . The adjustment block 371 is fixed by bolts 372 into a plurality of screw holes provided in the side wall of the cylinder 2 . The adjustment block 371 has a flat plate portion on which a protrusion is formed, and a through hole is formed in the center, penetrating from the flat plate portion to the protrusion. The adjustment block 371 is fixed to the side wall of the cylinder 2 by a plurality of bolts 372 at the flat plate portion outside the protrusion. The through hole of the adjustment block 371 has a large inner diameter portion from the hydraulic chamber 8 side to halfway up the convex portion, and a small inner diameter portion on the end face side of the convex portion, and a female thread is formed on the inner surface side of the small inner diameter portion on the end face side of the convex portion.

[0058] A pin through hole is formed in the side of the cylinder 2 which is coaxial with the through hole of the adjustment block 371, and an inner circumferential groove is formed around the entire inner surface of this pin through hole, and an O-ring 375 is arranged to seal the oil in the hydraulic chamber 8. The adjustment pin 373 has a male thread formed on one end and an unthreaded cylindrical shape on the other end. The male thread portion on one end of this adjustment pin 373 screws into the female thread of the adjustment block 371, and the tip of the cylindrical portion on the other end passes through the pin through hole of the cylinder 2 and reaches the inside of the hydraulic chamber 8. The position of the tip of the adjustment pin 373 within the hydraulic chamber 8 can be adjusted by adjusting the amount of insertion of the male thread portion. After the position is adjusted, the adjustment pin 373 is fixed by a radial set screw 374 provided on the protruding portion of the adjustment block 371 (see FIG. 5(a)).

[0059] FIG. 5 illustrates a state in which the thrust magnification device 1 is operated by advancing the input rod 101 from the initial state described in the first embodiment. As shown in FIG. 5, when the thrust magnification device 1 is in operation, an end face of a lock bolt 362 attached to the tip of the input rod 101 abuts against an adjustment pin 373, thereby regulating the amount of forward movement of the input rod 101. The operation method of the thrust magnification device 1 of the second embodiment and the operation for returning it to the initial state are similar to those of the first embodiment.

[0060] As described above, according to the thrust magnification device 1 of the second embodiment, the position of the forward movement end of the input rod 101 can be adjusted by adjusting the screw-in amount of the adjustment pin 373 from outside the forward movement adjustment unit 370 without disassembling the thrust magnification device 1. In addition, the stroke of the input rod 101 in the input side actuator (air cylinder 100, electric cylinder, etc.) can be adjusted. Therefore, the stroke adjustment of the output rod 72 can be performed by adjusting the stroke of the input side actuator. Furthermore, since the amount of advancement of the input rod 101 can be adjusted, it is possible to assemble an input side actuator having a longer stroke than the input side actuator installed according to the initial design specifications. In addition, since an advance adjustment unit 370 and a retreat stopper 361 are provided to regulate the advancement and retreat of the input rod 101, even if the electric cylinder attached as the input side actuator malfunctions and runs out of control, the thrust magnification device 1 can be stopped without being damaged.

[0061] Next, a thrust magnification device 1 according to a third embodiment will be described. In the thrust magnification device 1 of the first and second embodiments described above, the air cylinder 100 is attached to the side of the cylinder 2, so that the input axial direction (axial direction of the input rod 101) and the output axial direction (axial direction of the output rod 72) are perpendicular to each other. In contrast, the thrust magnification device 1 of the third embodiment is configured so that the input shaft and the output shaft coincide with each other.

[0062] Fig. 6 shows a state in which an air cylinder 100 is attached to the thrust magnification device 1 according to the third embodiment. Fig. 6(a) and (c) show a cross section in the thrust direction (AA cross section), and Fig. 6(b) shows a cross section (BB cross section) from above in a horizontal plane perpendicular to the center line of the input rod 101. Fig. 6(a) shows the initial state of the thrust magnification device 1, and Fig. 6(c) shows the operating state. As shown in FIG. 6, in the thrust magnification device 1 of the third embodiment, an axial through hole is formed in the axial direction of the cylinder 2, and an abutment wall 4x is formed near the center of the axial through hole in the axial direction. The piston portion 71 abuts against the output side (lower side in the drawing) surface of this abutment wall 4x, and the retraction stopper 361 attached to the tip of the input rod 101 abuts against the opposite input side (upper side in the drawing) surface. Grooves (not shown) are formed radially from the center on the input side surface of the abutment wall 4x to maintain communication between the input side hydraulic chamber 8b and the output side hydraulic chamber 8a (see FIG. 6(c)) even when the rearward stopper 361 abuts against the abutment wall 4x. There may be one or more grooves for communicating between the hydraulic chamber 8b and the hydraulic chamber 8a. In addition, instead of a groove in the abutment wall 4x, a communication hole (e.g., an axial through hole) that connects the hydraulic chamber 8b and the hydraulic chamber 8a when the rearward stopper 361 abuts against the abutment wall 4x may be provided in the abutment wall 4x. Similar to the contact wall 4w of the first embodiment, the contact wall 4x has a circular through hole formed in the center, and thus has an overall flange shape that protrudes inwardly of the cylinder 2. However, since the diameter of the through hole in the center of the contact wall 4x has a function of restricting the forward movement of the input rod 101 by abutting against the rearward stopper 361, the diameter of the through hole is formed to be smaller than the inner diameter of the rearward stopper 361, and thus is smaller than the through hole of the contact wall 4w. The structure of the thrust magnification device 1 on the output side of the contact wall 4x is formed similarly to the structure of the thrust magnification device 1 on the output side of the contact wall 4w in the first embodiment.

[0063] As shown in FIG. 6(b), three of the four side surfaces of the cylinder 2 have side through holes formed on the input side (upper side of the drawing) of the abutment wall 4x, and each of the side covers 3d to 3f is fixed by a plurality of pressing bolts 33d to 33f. Each side cover 3d to 3f has a peripheral wall with an inner diameter substantially the same as the inner diameter of the side through hole of the cylinder 2, which protrudes toward the hydraulic chamber 8, and an outer circumferential groove is formed around the entire outer circumferential surface of this peripheral wall, in which an O-ring is disposed to seal the oil in the hydraulic chamber 8.

[0064] An input-side lid 3t is fixed to the cylinder 2 by a pressing bolt 33t on the input side of the axial through hole in the cylinder 2. This input-side lid 3t is for attaching an input actuator such as an air cylinder 100 to the thrust magnification device 1 later. The input side lid 3t functions in the same manner as the input side lid 3 and the lid adapter 4 in the first embodiment. In the first embodiment, the input side lid 3 and the lid adapter 4 are formed separately and fixed with a holding bolt 44, but the input side lid 3t in this embodiment is formed as a single unit and functions as an input lid portion.

[0065] The input side lid 3t, like the lid adapter 4, has an input rod through hole formed in the center, through which the input rod 101 of the air cylinder 100 to be attached later is inserted. Similar to the first embodiment, a rearward stopper 361 is fixed to the tip of the input rod 101 by a stop bolt 362 in a state in which the interference avoidance condition of formula (1) is satisfied. As a result, similarly to the first embodiment, in the initial state of Figure 6(a), the rearward movement is restricted by the rearward stopper 361 abutting against the end face of the input side lid 3t on the hydraulic chamber 8 side, and interference between the step portion (flat edge 151, see Figure 6(c)) of the input rod 101 and the O-ring 47 is avoided.

[0066] The operation of the thrust magnification device 1 of the third embodiment is similar to that of the first embodiment. That is, from the initial state shown in FIG. 6(a), by operating the air cylinder 100 to move the input rod 101 forward, the piston portion 71 separates from the abutment wall 4x and the output rod 72 moves forward by the hydraulic stroke OS. In the case of the input rod 101 of the air cylinder 100 shown in FIG. 6, since the input stroke is short, the input rod 101 stops in front of the contact wall 4x in the most forward state. In contrast, when an air cylinder 100 with a longer input stroke is attached, the end face of the rearward stopper 361 on the side of the stop bolt 362 abuts against the abutment wall 4x, thereby restricting the movement in the forward direction. In this way, the contact wall 4x of the thrust magnification device 1 in the third embodiment functions as an advancement restriction means for restricting the forward movement of the input rod 101 when the air cylinder 100 with a long input stroke is attached. By changing the thickness of the rearward stopper 361, it is possible to change the contact position between the contact wall 4x and the rearward stopper 361 and thereby change the forward end stop position of the input rod 101. For example, by using a thicker rearward stopper 361, it is possible to stop the input rod 101 further forward.

[0067] Next, a fourth embodiment will be described. In the thrust magnification devices 1 of the first to third embodiments, the female-threaded air cylinders 100 described with reference to FIGS. 10(a) to 10(d) are attached later as the air cylinders 100. FIG. In contrast, in the thrust magnification device 1 of the fourth embodiment, the male thread type air cylinder 100 described with reference to FIG. 10(e) is attached later. FIG. 7 shows the state in which a male-threaded air cylinder 100 is attached to the thrust magnification device 1 of the fourth embodiment, where (a) shows a cross section (AA cross section) in the thrust direction (direction of the center line) in the operating state, and (b) shows the BB cross section from above in the initial state.

[0068] The thrust magnification device 1 of the fourth embodiment is the same as the thrust magnification device 1 described in the second embodiment (see FIG. 5 ) except for the retreat restriction means (return stoppers 361, 365) attached to the input rod 101, and an advance adjustment unit 370 is disposed on the side wall of the cylinder 2.

[0069] 7 and 10, a small diameter portion 153 is formed at the tip of an input rod 101 of a male-threaded air cylinder 100, and a male thread is formed on the outer circumferential surface of this small diameter portion 153. In addition, a flat chamfer 151 for use with a wrench is formed on the front side (the intake / exhaust hole 103 side) of the small diameter portion 153, which is a stepped portion. In this embodiment, a retraction stopper 365 that functions as a retraction restriction means is provided on the male thread 154 of the input rod 101 . The retraction stopper 365 is formed in a disk shape, and has a through hole with a female screw on the inner peripheral surface at the center. A screw hole is formed in the outer peripheral surface of the retraction stopper 365, penetrating in the radial direction, and the retraction stopper 365 is fixed with a set screw 366 (see FIG. 7(b)).

[0070] The fixed position of the rearward stopper 365 on the small diameter portion 153 of the input rod 101 is a position that satisfies the interference avoidance condition shown in the above-mentioned formula (1). In formula (1), the step distance D1 when the rearward stopper 365 is used is the distance from the position of the step part such as the flat cut 151 closest to the body of the air cylinder 100 to the contact surface P between the rearward stopper 365 and the lid adapter 4. Also, the ring distance R1 is the distance from the O-ring 47 closest to the rearward stopper 365 to the contact surface P. In the case of a male-threaded input rod 101, the fixed position of the retraction stopper 365 can be adjusted within the range of the male thread 154 formed on the small diameter portion 153, thereby satisfying the interference avoidance condition.

[0071] When the thrust magnification device 1 of the fourth embodiment is operated, as shown in FIG. 7(a), the tip of the input rod 101 abuts against the adjustment pin 373, thereby restricting the movement in the forward direction.

[0072] In the fourth embodiment described above, the thrust magnification device 1 has been explained using the thrust magnification device 1 of the second embodiment as an example, but the retract stopper 365 can also be used as in the fourth embodiment when a male-screw type input actuator (air cylinder 100 or electric cylinder) is retrofitted to the thrust magnification device 1 described in the first or third embodiment.

[0073] Next, a fifth embodiment will be described. In the first to fourth embodiments, the thrust magnification device 1 is configured so that the tip of the output rod 72 moves in a direction away from the cylinder as the input rod 101 of the attached air cylinder 100 advances within the hydraulic chamber 8. That is, this is a push-type thrust magnification device 1 in which the thrust input from the input rod 101 is magnified in the hydraulic chamber 8 and output in the external direction (pushing direction) as seen from the device. In contrast, the thrust magnification device 1 of the fifth embodiment is a retraction type thrust magnification device 1 in which the thrust input from the input rod 101 and magnified in the hydraulic chamber 8 is output in a direction that retracts the tip of the output rod 72 into the inside of the device.

[0074] 8 shows the state in which a female-thread type air cylinder 100 is attached to the thrust magnification device 1 of the fifth embodiment, where (a) and (d) show a cross section (AA cross section) in the thrust direction (direction of the center line), (b) shows the BB cross section from above, and (c) shows the right side view. Also, Fig. 8(a) shows the initial state, and (d) shows the operating state. The thrust magnification device 1 is formed in a rectangular parallelepiped shape that is long in the vertical direction (longitudinal direction) of FIG. 8(a), and has an axial through hole that penetrates in the vertical direction and partially forms a hydraulic chamber 8. An abutment wall 4w is formed along the entire periphery of the inner peripheral wall surface at a position above the center of the axial through-hole in the cylinder 2. This abutment wall 4w has a circular through-hole formed in the center, and thus has a flange shape that protrudes inwardly of the cylinder 2 as a whole. The contact wall 4w has a function of determining the position of the piston portion 71 in the initial state by abutting the surface of the piston portion 71 on the output rod 72 side.

[0075] In the lower part of the cylinder 2, an output side cover 5 through which an output rod 72 is inserted and a stop cover 6 are fixed to the end of the cylinder 2 by a pressing bolt 54, in the same manner as in the first embodiment. In this embodiment, unlike the first embodiment, the output side lid 5 and the piston portion 71 are not provided with the anti-rotation pin 75, the guide pin 77, and the coil spring 57. However, in this embodiment and a sixth embodiment described later, the upper lid 3a may be provided with holes 55, 57a, and the piston portion 71 may be provided with pin holes 74, 76 on the opposing side of the upper lid 3a, so that the anti-rotation pin 75, the guide pin 77, and the coil spring 57 may be provided as in the first embodiment. Meanwhile, an upper lid 3a is fixed with eight holding bolts 33a to the top of the cylinder 2. The upper lid 3a has a convex portion of approximately the same diameter formed thereon to be inserted into the axial through-hole of the cylinder 2, and a groove is formed around the entire outer periphery of the upper lid 3a, in which an O-ring is disposed.

[0076] In the thrust magnification device 1 of the first embodiment, a piston portion 71 is disposed below a contact wall 4w, and a hydraulic chamber 8 is formed on the upper side. In contrast, in the thrust magnification device 1 of this embodiment, as shown in FIG. 8(a), a piston portion 71 is disposed on the upper side of the contact wall 4w, and the lower side forms the hydraulic chamber 8. An output rod 72 provided on one side of the piston portion 71 passes through the hydraulic chamber 8, the output side lid 5, and the stopper lid 6, and extends to the output side (lower side in the drawing) of the cylinder 2. A bolt hole 72a is formed on the open end side of the output rod 72, but a cavity 73 (see FIG. 1) is not formed.

[0077] An air chamber 9 is formed between the surface of the piston portion 71 on the side where the output rod 72 is not disposed and the upper lid 3a. An L-shaped intake and exhaust hole 36a is formed in the upper lid 3a, connecting the air chamber 9 with the outside. The intake and exhaust hole 36a extends axially from the surface facing the piston portion 71, then bends and extends radially, penetrating through to the side surface of the upper lid 3a. An intake and exhaust port 24 connected to the intake and exhaust hole 36a is provided on the side surface of the upper lid 3a. As in the first embodiment, it is also possible to provide a through hole connected to the air chamber 9 and an intake / exhaust port 24 in the side wall of the cylinder 2.

[0078] A side input through hole corresponding to the side input through hole 31 (see FIG. 3) in the first embodiment is formed in the side surface of the cylinder 2 below the contact wall 4w. In this side input through hole, the input side lid 3 and the lid adapter 4 fixed with a pressing bolt 44 are fixed to the side wall of the cylinder 2 with a pressing bolt 33, as in the first embodiment. In addition, an air cylinder 100 is attached to the lid adapter 4 by a pressure bolt 109, and a rearward stopper 361 is screwed to the tip of the input rod 101 by a locking bolt 362 in a state that satisfies the interference avoidance condition of equation (1). The air cylinder 100 that can be retrofitted to the thrust magnification device 1 of the fifth embodiment must have a maximum stroke at the tip of the input rod 101 when the retraction stopper 361 (retraction stopper 365 in the case of a male thread type) is attached just before contacting the output rod 72. On the other side surface of the cylinder 2, a through hole for oil supply and an oil supply plug 22 are provided below the contact wall 4w. The procedure for retrofitting the air cylinder 100 to the thrust magnification device 1 of this embodiment is similar to that of the embodiment described with reference to FIG.

[0079] Next, the operation of the thrust magnification device 1 to which the air cylinder 100 is attached in this embodiment will be described. The thrust magnification device 1 is in an initial state in which the thrust is not magnified, as shown in FIGS. 8(a) and 8(c). That is, in the initial state, the tip of the input rod 101 of the air cylinder 100 is not pushed out, and the thrust magnifying device 1 is in a state where the end face of the piston 71 on the output rod 72 side is in contact with the contact wall 4w. In this state, the piston 71 is at the farthest position from the upper lid 3a, and the tip of the output rod 72 connected to the piston 71 protrudes most outward from the output-side lid 5.

[0080] When using the thrust amplification device 1 with the air cylinder 100 attached, in the initial state, the intake / exhaust port 24 of the thrust amplification device 1 and the intake / exhaust hole 103 of the air cylinder 100 are opened so that the internal air can escape. By supplying air from the intake / exhaust hole 102 in this state, a piston (not shown) inside the air cylinder 100 is pushed toward the thrust amplification device 1 side, and air escapes from the intake / exhaust hole 103. As the piston moves, the input rod 101 is pushed out and enters the hydraulic chamber 8. Due to the movement of this input rod 101, the piston portion 71 and the output rod 72 move by the hydraulic stroke to the opposite side (upper lid 3a side) of the hydraulic chamber 8. As the piston portion 71 moves, the volume of the air chamber 9 decreases by that amount, and the internal air escapes from the intake / exhaust port 24.

[0081] And from the tip of the output rod 72, a pulling force is generated with an amplified (expanded) amplified thrust Fp by hydraulic pressure with respect to the thrust of the air cylinder 100, that is, the input thrust Fi from the tip of the input rod 101. Regarding this input thrust Fi and amplified thrust Fp, they are the same as the formula (2) described in the first embodiment.

[0082] Here, if the area of the tip surface of the input rod 101 is S1 and the area of the piston portion 71 (the area obtained by subtracting the radial cross-sectional area of the output rod 72 from the radial cross-sectional area of the piston portion 71) is S2, the force that the piston portion 71 receives from the oil in the hydraulic chamber 8, that is, the pulling amplified thrust Fp output from the tip of the output rod 72 is as described in the above formula (2). Here, when the area of the radial cross-section of the portion other than the flattened part 151 of the input rod 101 is S1 and the area in contact with the oil in the hydraulic chamber 8 in the piston portion 71 (the area obtained by subtracting the radial cross-sectional area of the output rod 72 from the radial cross-sectional area of the piston portion 71) is S2, the thrust amplification device 1 of this embodiment also has the relationship of S1 < S2, similar to the first embodiment. Therefore, from the output rod 72, a pulling force (force in the direction of the upper lid 3a) with an amplified amplified thrust Fp with respect to the input thrust Fi from the input rod 101 can be output.

[0083] Note that the operation state of FIG. 8(d) in which the thrust magnification device 1 is outputting an expanded thrust (retraction force) is returned to the initial state of FIG. 8(a) as follows. That is, the intake / exhaust hole 102 (not shown) is opened and air is supplied from the intake / exhaust hole 103, whereby the input rod 101 of the air cylinder 100 is moved backward from the hydraulic chamber 8. As a result, the hydraulic chamber 8 is restored to the volume of the space that was previously occupied by the input rod 101, and since negative pressure is applied to the piston portion 71 on the hydraulic chamber 8 side and atmospheric pressure is applied to the air chamber 9, the piston portion 71 moves until it abuts against the contact wall 4w. When returning to the above-described initial state, since a retraction stopper 361 is attached to the tip of the input rod 101, the retraction is restricted when the retraction stopper 361 abuts against the lid adapter 4, so that interference between the stepped portions such as the flat edge 151 and the O-ring 47 is avoided. In order to more reliably return to the initial state, air may be supplied from the intake / exhaust hole 103 and air may also be supplied to the air chamber 9 from the intake / exhaust port 24 of the thrust magnification device 1, which has been in an open state.

[0084] Next, a sixth embodiment of the thrust magnification device 1 will be described. In the fifth embodiment, a retraction-type thrust magnification device 1 that acts on the magnified thrust in a retracting direction has been described. In this thrust magnification device 1, the side input through-hole of the cylinder 2 is formed at a position where an area of ​​its inner circumferential surface extended in the axial direction interferes with the outer circumferential surface of the output rod 72. Therefore, as a condition for using the retrofitted air cylinder 100, the stroke length when the input rod 101 is fully advanced must be a length that does not allow the tip end (including the locking bolt 362) to come into contact with the output rod 72. In contrast, in the thrust magnification device 1 of the sixth embodiment, the lid adapter 4 and the input side lid 3 are arranged at a position where the extension line of the center line of the input rod through hole of the lid adapter 4 (the center line of the input rod 101) is farther away from the center line of the output rod 72 than the distance obtained by adding the radius of the input rod through hole and the radius of the output rod 72. Specifically, a side input recess 31b corresponding to the side input through hole 31 (see Figure 3) of the first embodiment is formed in the cylinder 2, and is shifted to a position where it does not interfere with the outer peripheral surface of the output rod 72 even when the input rod 101 advances, and is formed so that part or all of the radial cross section passes through the hydraulic chamber 8.

[0085] 9 shows the state in which the air cylinder 100 is attached to the thrust magnification device 1 of the sixth embodiment, where (a) shows a cross section (AA cross section) in the thrust direction (direction of the center line), (b) shows the cross section BB from above, and (c) shows a right side view. Both (a) and (b) of FIG. 9 show the operating state. In the following embodiment, the description of the same or corresponding parts as in the fifth embodiment will be omitted and only the differences will be described.

[0086] As shown in Figures 9(b) and (c), in the thrust magnification device 1 of the sixth embodiment, a thick side portion 2a is formed on one side of a cylinder 2 (the upper side in Figure 9(b)) so as to be thicker than that of the fifth embodiment. In the thick-walled side portion 2a, a side input recess 31b that communicates with the hydraulic chamber 8a on the side surface is formed at a position lower than the contact wall 4w, and the inner diameter of the side input recess 31b is formed larger than the outer diameter of the rearward stopper 361. The side input recess 31b constitutes the hydraulic chamber 8c by receiving oil from the oil filler plug 22. The open end of the side input recess 31b (the side surface of the cylinder 2) is formed with a larger inner diameter on the open end side, similar to the side input through hole 31 in the first embodiment. The input side lid 3 and the lid adapter 4 fixed with the pressing bolt 44 are fixed to the open end of this side input recess 31b with the pressing bolt 33, similar to the first embodiment.

[0087] An air cylinder 100 is attached to the lid adapter 4 by a retaining bolt 109. A rearward stopper 361 is screwed to the tip of the input rod 101 by a locking bolt 362 in a state where the interference avoidance condition of formula (1) is satisfied. As a result, when the thrust magnification device 1 returns to its initial state, the rearward movement of the input rod 101 is restricted, and interference between the O-ring 47 and stepped portions such as the flat chamfer 151 is avoided. Meanwhile, in the thrust magnification device 1 of this embodiment, an advance adjustment unit 370 is disposed on the side surface of the cylinder 2 on the bottom side of the side input recess 31b, as in the second embodiment. With this, when the thrust magnification device 1 is in an operating state, an end face of a lock bolt 362 attached to the tip of the input rod 101 abuts against an adjustment pin 373, thereby restricting forward movement of the input rod 101. Note that the provision of the advance adjustment unit 370 is optional and may be omitted. [Explanation of symbols]

[0088] 1 Thrust augmentation device 2 Cylinder 2a Thick side wall part 3, 3t Input side lid (lid part) 3a Top lid 3b, 3c, 3d~3f Side lid 4 Lid adapter 4w, 4x abutment wall 5 Output side cover 6 Stop cover 7 Hydraulic piston 8, 8a~8c Hydraulic chamber 9 Air chamber 21 Fuel filler port 22 Fuel filler plug 24 Intake and exhaust port 31 Side input through hole 31b Side input recess 36a Intake and exhaust holes 39, 47, 49, 59 O-rings 42, 51 Guide bush 57 Coil spring 65 Dust seal 71 Piston part 72 Output rod 72a Bolt hole 73 Hollow portion 77 Guide pin 100 Air cylinder 101 Input rod 102 Intake and exhaust hole 103 Intake and exhaust hole 109 Press bolt 151 Flat 152 Female thread 153 Small diameter section 154 Male thread 361, 365 Retract stopper 362 Locking bolt 363 Recess 370 Advance adjustment unit 371 Adjustment block 373 Adjustment pin 375 O-ring D1, D2 Step distance P Contact surface Q Contact surface R1, R2 Ring distance

Claims

1. 1. A thrust magnifying device that amplifies and outputs a thrust input from an input actuator by connecting the input actuator, A cylinder having an axial through hole formed in a thrust direction; A fluid chamber formed in the cylinder; a fluid piston having a piston portion disposed in the axial through hole, one side surface of which constitutes a part of an inner wall surface of the fluid chamber and which moves in a thrust direction, and an output rod connected to the piston portion and which outputs the expanded thrust; an output side cover portion connected to one end side of the cylinder and having a through hole through which the output rod moves in a thrust direction; an input cover portion provided at an open end of a through hole formed in the cylinder and communicating with the fluid chamber, the input cover portion having an opening through which an input rod of the input actuator is inserted; an input fixing means for fixing the input actuator with the input rod inserted through the opening; a seal means disposed on an inner peripheral surface of the opening for sealing between the opening and the input rod; a retraction restriction means for restricting a range of movement of the input rod in a retraction direction within the fluid chamber; A thrust magnification device comprising:

2. the retraction restricting means restricts the retraction movement of the input rod such that a step end position of a step portion formed at the tip portion of the input rod, which is farthest from the tip of the input rod, stops at a position closer to the fluid chamber than a shield end position of the shield means which is closest to the fluid chamber.

2. The thrust magnification system of claim 1 .

3. 3. The thrust magnification device according to claim 2, wherein the retreat restriction means includes a retreat stopper that has an outer diameter larger than an inner diameter of the opening and is disposed at a tip end of the input rod in a state where an interference avoidance condition of "step distance D1 < ring distance R1" is satisfied. Here, the distance from the step end position to the abutment surface P between the rearward stopper and the input lid portion is the step distance D1, and the distance from the shield end position to the abutment surface P is the ring distance R1.

4. A forward movement restricting means is provided for restricting forward movement of the input rod so that the input rod stops at a position before an inner surface of the cylinder that faces the tip surface of the input rod.

4. The thrust magnification device according to claim 1, 2, or 3.

5. A forward movement restricting means having an adjustment pin that penetrates the side surface of the cylinder facing the tip surface of the input rod and restricts forward movement of the input rod by abutting the tip of one end side against the input rod.

5. The thrust magnification device according to claim 1, wherein the thrust magnification device is a thrust magnification device.

6. The forward movement restricting means has an adjustment block fixed to an outer wall surface of the cylinder, The adjustment pin has a male screw formed on the other end thereof, The adjustment block has a through hole through which the adjustment pin is inserted and on which a female thread is formed to screw into a male thread of the adjustment pin.

6. The thrust magnification system of claim 5.

7. A side through hole is formed in a side wall of the cylinder, The input cover is disposed at an open end of the side through hole.

7. The thrust magnification device according to claim 1, wherein the thrust magnification device is a thrust magnification device.

8. The input lid portion is disposed at an open end on the other end side of the axial through hole.

4. The thrust magnification device according to claim 1, wherein the thrust magnification device is a thrust force magnification device.

9. a surface of the piston portion on a side to which the output rod is not connected constitutes a part of a partition wall of the fluid chamber; The thrust magnification device according to any one of claims 1 to 8.

10. a surface of the piston portion on a side to which the output rod is connected constitutes a part of a partition wall of the fluid chamber, The output rod acts on the amplified thrust in a pulling direction. The thrust magnification device according to any one of claims 1 to 8.

11. the input lid portion is disposed at a position where an extension line of a center line of the opening portion is spaced apart from a center line of the output rod by a distance greater than a sum of a radius of the opening portion and a radius of the output rod. The thrust augmentation system of claim 10.

Images