Three-position pneumatic or hydraulic power cylinder

Abstract

The present invention relates to a hydraulic cylinder device and can be used in a vehicle transmission. A three-position pneumatic or hydraulic cylinder consists of a housing with end caps, two pistons, a rod, and a working fluid supply passage. Each piston is configured to move limitedly along the rod due to the central protrusion of the piston and the peripheral protrusion on the rod, and is configured to move limitedly within the housing. The central protrusion is configured in the form of a bushing, and an annular protrusion is configured on the inner surface of the housing. The bushing and the protrusion form a sealed movable coupling of the shaft / aperture type. Separate passages are provided for supplying the working fluid to the chambers formed by each piston and the corresponding end of the housing, and a shared passage is provided for supplying the working fluid to the chambers formed by each piston and the central protrusion and the bushing; alternatively, separate passages are provided for supplying the working fluid to the chambers formed by each piston and the central protrusion and the bushing, and a shared passage is provided for supplying the working fluid to the chambers formed by each piston and the corresponding end of the housing.

Description

Technical Field

[0001] The present invention relates to positive displacement pneumatic or hydraulic actuators, and more particularly, to pneumatic (hydraulic) cylinder devices and can be used in robotic production lines, actuators for various purpose machines, including vehicle transmissions. Background Art

[0002] For example, a synchronizer shift hydraulic actuator (patent RU2545543C2) is known. The actuator includes a cylinder and a piston, the piston being arranged to move within the cylinder so as to separate a first chamber from a second chamber.

[0003] When the actuator is in the first engaged position, the volume of the first chamber is minimized, and when the actuator is in the second engaged position, the volume of the second chamber is minimized. The piston also defines a third chamber in the cylinder, the volume of which is minimized when the actuator is in the intermediate position.

[0004] This actuator is a product with complex technology. Specifically, its performance directly depends on the pressurization accuracy in a specific chamber.

[0005] A three-position hydraulic cylinder (patent RU2079007C1) is known, which includes a housing with windows for load connection and working fluid supply, wherein the cavity is closed by a cover, a drilled piston and a plunger and a cover interacting therewith are located therein, and the plunger is located in a piston hole equipped with a stop restricting its stroke.

[0006] A pin positioned perpendicular to the longitudinal axis of the body serves as a working element for interacting with the load. The disadvantage of this design is the inability to move the working element to both ends of the housing.

[0007] A three-position pneumatic cylinder (patent NSh 87364V) was selected as a prototype, which consists of a housing with end caps, two pistons, a rod and channels for the working fluid. The pistons divide the interior of the cylinder into three chambers, wherein each piston is configured to move limitedly along the rod due to a central protrusion that separates the piston from the peripheral protrusion on the rod, and is configured to move limitedly within the housing due to a protrusion formed on the inner surface of the housing. A thrust element is fixed on the rod between the two pistons, and an inlet port of the working fluid (air) supply channel is to the chamber between the pistons.

[0008] The disadvantages of the known prototype device are the following design features:

[0009] - Large size due to the presence of an upper end cap.

[0010] - It is impossible to implement an additional rod outlet from one of the cylinder end faces and, for example, a vertically mounted pin.

[0011] The end face of the protrusion (bushing) on the rod (in the working fluid supply area) acts as a piston, thus affecting any rod movement. That is, in order to set the rod to the middle or neutral position, additional energy (pressure) of the working fluid is required.

[0012] - The potential pressure difference when the rod is in the middle position may cause the so-called rod bounce beyond the middle position and then return (travel) to the middle position. This factor is disadvantageous in devices according to this working function.

[0013] - The alignment of the rod is ensured by contact with the cover and the piston. If the rod load is large, this may affect the uninterrupted operation time of the device. The alignment of the sealing points at least seems problematic. NSh 87364V provides increased piston fit dimensions to ensure rod alignment, and this increases the device size, weight, and material consumption.

[0014] Using more complex manufacturing designs, such as a stop protrusion in the middle of the bushing should be specifically fitted relative to the working fluid outlet or an obviously complex slot system design is adopted, while ensuring the impact strength; the use of retaining rings also complicates the design; the use of additional end caps that should be fixed and sealed. Summary of the Invention

[0015] The object of the present invention is to provide a device without the above-mentioned disadvantages. The technical result is to simplify the design and improve the reliability, speed, and accuracy of the device.

[0016] This problem is solved by a three-position pneumatic or hydraulic cylinder, which consists of a housing with end caps (walls), two pistons, a rod, and working fluid channels. Each piston is configured to move limitedly along the rod due to the central protrusion that separates the piston from the peripheral protrusion on the rod and move limitedly within the housing. Wherein, the central protrusion is configured in the form of a bushing, and an annular protrusion is configured on the inner surface of the housing. Wherein, the bushing and the protrusion form a sealed movable coupling of the shaft / open type. In fact, the proposed solution results in the formation of four chambers inside the housing formed by the end caps (walls), two pistons, and a partition formed by the bushing and the annular protrusion.

[0017] The protrusion is understood to mean any component that restricts the movement of the piston, such as a part of the bushing, housing, or rod. Detailed Description of the Invention

[0018] By implementing the working fluid supply channels, two preferred embodiments of the present invention are proposed and determined.

[0019] In a first preferred embodiment, the working fluid supply channels are implemented as follows: separate channels leading to the chambers formed by each piston and the corresponding end (end cap) of the housing, and a shared channel leading to the chambers formed by each piston and the central protrusion and the bushing.

[0020] In a second preferred embodiment, the working fluid supply channels are implemented as follows: separate channels leading to the chambers formed by each piston and the central protrusion and the bushing, and a shared channel leading to the chambers formed by each piston and the corresponding end (end cap) of the housing.

[0021] All embodiments can be supplemented by positioning at least one load interaction pin inclined with respect to the rod axis in the holes of the annular protrusion.

[0022] In one device embodiment, only the above-mentioned pin elements are provided for load interaction. In principle, depending on the specific use of the device, one or two rod outlets, one or more pins can be used in various combinations to implement the design. The bushing with pins can also be rotated fanwise around the bushing axis.

[0023] The present invention is illustrated by graphical materials: prototype drawings and photographs.

[0024] Figure 1 Longitudinal sectional view showing the central (middle) position of the first preferred embodiment of the cylinder.

[0025] Figure 2 Longitudinal sectional view showing the rightmost position of the first preferred embodiment of the cylinder.

[0026] Figure 3 and Figure 4 Longitudinal sectional view showing the central (middle) position of the second preferred embodiment of the cylinder with a working fluid supply channel of a different design.

[0027] Figure 5 Longitudinal sectional view showing the rightmost position of the second preferred embodiment of the cylinder.

[0028] Figure 6 General view showing a prototype three-position cylinder with two end rod elements.

[0029] Figure 7 Exploded view showing a prototype three-position cylinder with two end rod elements.

[0030] Figure 8 Exploded view showing a prototype three-position cylinder with one end rod element.

[0031] The three - way cylinder consists of a housing 1 in which a rod is located. The housing 1 includes a central part, a cylindrical bushing 2 with two protrusions for pistons 3 and 4, and can move freely inside the cylindrical part of the housing 1, on the bushing 2, two end caps 5 and 6, end rod elements 7 and 8, and side pins 9. Preferably, the rod consists of several rigidly connected parts: the bushing 2 made of low - friction sliding material, the ends 7, 8 with peripheral protrusions, and the side pins 9. The device also includes working fluid (compressed air or liquid) supply channels A, B, and C.

[0032] In a first preferred embodiment ( Figure 1 and Figure 2 ), separate channels A and C leading to the chambers formed by each of the pistons 3, 4 and the corresponding ends (caps 5 and 6) of the housing can be provided in the housing and caps 5 and 6. A shared channel B leading to the chamber formed by each of the pistons 3, 4, the central protrusion, and the bushing 2 can be provided in the protrusion of the housing 1.

[0033] In another preferred embodiment ( Figure 3 , Figure 4 , Figure 5 ), separate channels A and C leading to the chambers formed by each piston and the central protrusion and the bushing are provided in the protruding part of the housing 1, and a shared channel B leading to the chambers formed by each of the pistons 3, 4 and the corresponding ends (end caps 5, 6) can be provided in the wall of the housing 1 ( Figure 3 and Figure 5 ) or in the bushing 2 ( Figure 4 ).

[0034] The device can operate with any number of output load interaction elements (end elements 7, 8, pins 9). When using the device without end elements 7, 8, protruding piston stroke limiters (pistons 3, 4) should be installed on the bushing 2 and caps (caps 5, 6) without rod holes. A prototype device with one end rod element is as shown in Figure 8 .

[0035] The operation of the device according to the first preferred embodiment (compressed air) is as follows.

[0036] When compressed air is supplied to channel B, piston 3 moves to the left and piston 4 moves to the right. The pistons reach the protrusions of end caps 5, 6 and rest against the retaining protrusions of rods 7 and 8 to set the bushing 2 in the middle position ( Figure 1 ). At this time, channels A and C are open to the atmosphere.

[0037] When compressed air is supplied to passage A, piston 3 moves to the right and, after reaching the projection of bushing 2, pushes it to the right. Then piston 3 abuts against the fixed projection of the main housing, and bushing 2 abuts against piston 4 on cover 6, thereby setting bushing 2 with elements 7, 8 and pin 9 to the extreme right position( Figure 2 ). At this time, passages B and C are open to the atmosphere.

[0038] The movement to the extreme left position is carried out in the reverse (mirror) order with respect to the movement to the extreme right position.

[0039] If the projections of the main housing, end covers 5, 6 and bushing 2 have an asymmetrical design, the rod can be held in the desired (shifted) intermediate position with respect to the central (intermediate) position.

[0040] The operation of the device according to the second preferred embodiment (compressed air) is as follows( Figure 3 、 Figure 4 ).

[0041] The device can also operate together with any number of output load interacting elements (end elements 7, 8, pin 9). When using a device without end elements 7, 8, protruding piston stroke limiters (pistons 3, 4) should be installed on bushing 2 and covers (covers 5, 6) without rod holes (as in the first preferred embodiment)( Figure 8 ).

[0042] When compressed air is supplied to passage B, piston 3 moves to the right and piston 4 moves to the left. The pistons reach the projection of bushing 2 and abut against the housing to set bushing 2 with rods 7, 8 and pin 9 in the intermediate position. At this time, passages A and C are open to the atmosphere.

[0043] When compressed air is supplied to passage C, piston 4 moves to the right and moves bushing 2 to the right after reaching rod 8. Rod 7 abuts against piston 3, and bushing 2 with rods 7, 8 and pin 9 is set to the extreme right position. At this time, passages A and B are open to the atmosphere.

[0044] The movement to the extreme left position is carried out in the reverse (mirror) order with respect to the movement to the extreme right position.

[0045] If the main housing 1 and bushing 2 have an asymmetrical design, the rod can be held in the desired (shifted) intermediate position with respect to the central (intermediate) position.

[0046] The operating principle of the device under liquid pressure is similar to that of compressed air, but the passage of the main liquid line that does not bear high pressure during rod resetting should lead to the low-pressure main liquid line and the expansion tank.

[0047] Industrial applicability

[0048] The prototype device (without pin 9, Figure 6 , Figure 7 , Figure 8 ) demonstrated its operating ability during the test, solved the problems, and achieved the said technical effects.

[0049] No faults, partial engagement, and interruptions were recorded during the trial operation. It should also be noted that when reaching any of the said three positions, the rod (and / or pin) driving (moving) force is the same. Therefore, if it is ensured that all three positions are reached, the cylinder can be said to be a power cylinder. The driving (moving) device can also operate under low joint tightness, but to ensure that the force remains at the reached positions (under the working fluid pressure), appropriate tightness and sealing should be provided in the piston and end covers.

Claims

1. A three-position pneumatic or hydraulic power cylinder, characterized in that, Comprising a housing with end caps, two pistons, a rod, and a working fluid supply passage; The end caps are provided at two ends of the housing, the end caps are respectively provided with protrusions for restricting the pistons, and the inner surface of the housing is provided with an annular protrusion, and the annular protrusion is arranged between the two end caps; The rod is arranged inside the housing and is configured to be capable of limited movement within the housing; the two ends of the rod are respectively provided with peripheral protrusions, and a central protrusion is arranged between the two peripheral protrusions, and the central protrusion is not a piston; The central protrusion is configured in the form of a bushing and is sleeved into the annular protrusion to form a shaft / aperture type sealing movable coupling together with the annular protrusion; The two pistons are respectively arranged on the rod located on both sides of the annular protrusion, and due to the peripheral protrusions, the pistons perform limited movement along the rod between the peripheral protrusions and the annular protrusion; Each of the pistons, the housing, and the end cap forms a first chamber, and each of the pistons, the housing, the annular protrusion, and the central protrusion forms a second chamber, and each of the first chamber and the second chamber communicates with the working fluid supply passage.

2. The three-position pneumatic or hydraulic power cylinder according to claim 1, characterized in that The working fluid supply passage is realized as follows: a separate passage leading to each of the first chambers, and a shared passage leading to the two second chambers.

3. The three-position pneumatic or hydraulic power cylinder according to claim 1, characterized in that, The working fluid supply passage is realized as follows: a separate passage leading to each of the second chambers, and a shared passage leading to the two first chambers.

4. The three-position pneumatic or hydraulic power cylinder according to claim 1 or claim 2 or claim 3, characterized in that, At least one load interaction pin inclined to the rod axis is located in the hole of the annular protrusion.

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