Air chuck

Abstract

To provide an air chuck which prevents a work-piece from falling during non-electric conduction of an electromagnetic valve due to a power failure and so on.SOLUTION: A chuck unit 12 comprises: a first pressure chamber 26; and a second pressure chamber 28 provided on both sides of a piston 16 for driving a plurality of fingers 50. A valve unit 56 comprises: a first output air flow passage 74 which is connected to one of the first pressure chamber and the second pressure chamber; a second output air flow passage 76 which is connected to the other of the first pressure chamber and the second pressure chamber; a first electromagnetic valve 58 connected to the first output air flow passage; and a second electromagnetic valve 60 connected to the second output air flow passage. The first output air flow passage connects the first output air flow passage to an air supply source during energization conduction, and opens the first output air flow passage to atmosphere during non- energization conduction, and the second electromagnetic valve opens the second output air flow passage to atmosphere during energization conduction, and connects the second output air flow passage to the air supply source during non-energization conduction.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an air chuck that is attached to a robot arm or a transport device (hereinafter referred to as "robot arm, etc."). [Background technology]

[0002] Conventionally, there has been known a technology for providing an open / close chuck for gripping a workpiece on the tip side of a robot arm. For example, Patent Document 1 describes a robot hand that is composed of a hand main body that is attached to the robot arm and a hand tip that can be attached with a chuck for gripping a workpiece by driving an air cylinder, and the hand tip is detachable from the hand main body.

[0003] In the above robot hand, the hand body is provided with a plurality of solenoid valves required for driving the chuck, a flow path for supplying air to the input port of each solenoid valve, and a flow path for supplying air from the output port of each solenoid valve to the tip of the hand. This makes it possible for the hand body to accommodate a variety of hand tips, and also makes it unnecessary to arrange external piping for supplying air around the robot hand. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-149224 A Summary of the Invention [Problem to be solved by the invention]

[0005] In an open-close chuck that is driven by air using two solenoid valves, it is necessary to prevent the workpiece from falling when the solenoid valve is de-energized due to a power outage or the like. In this case, it should be noted that the open-close chuck can hold a workpiece by pinching it between the inside of a pair of fingers, or by expanding the pair of fingers and holding the workpiece on the outside. In particular, in an open-close chuck that has fewer external air pipes, it is not easy to change the solenoid valves or air pipes, and it is not easy to prevent the workpiece from falling depending on the holding form of the workpiece.

[0006] The present invention has been made in consideration of the above problems, and has an object to provide an air chuck that prevents a workpiece from falling when the solenoid valve is de-energized due to a power outage, etc. Another object is to provide an air chuck that easily prevents the workpiece from falling depending on the gripping form of the workpiece. [Means for solving the problem]

[0007] The air chuck according to the present invention comprises a chuck unit having a plurality of fingers and a valve unit attached to a robot arm or the like, the chuck unit having a first pressure chamber and a second pressure chamber provided on either side of a piston that drives the plurality of fingers, the valve unit having a first output air flow passage connected to one of the first pressure chamber and the second pressure chamber, a second output air flow passage connected to the other of the first pressure chamber and the second pressure chamber, a first solenoid valve connected to the first output air flow passage and a second solenoid valve connected to the second output air flow passage, the first solenoid valve connects the first output air flow passage to an air supply source when energized and opens the first output air flow passage to the atmosphere when deenergized, and the second solenoid valve opens the second output air flow passage to the atmosphere when energized and connects the second output air flow passage to the air supply source when deenergized. Preferably, the chuck unit is selectively connectable to the valve unit between a first rotation position and a second rotation position which have different angles around a central axis of the valve unit, and in the first rotation position, the first output air flow path is connected to the first pressure chamber and the second output air flow path is connected to the second pressure chamber, and in the second rotation position, the first output air flow path is connected to the second pressure chamber and the second output air flow path is connected to the first pressure chamber.

[0008] According to the above air chuck, it is possible to prevent the workpiece from falling when the solenoid valve is not energized due to a power outage or the like, and it is also possible to easily prevent the workpiece from falling depending on the gripping shape of the workpiece. Effect of the Invention

[0009] The air chuck according to the present invention combines two solenoid valves of a normally closed type and a normally open type, and therefore can prevent the workpiece from falling when the solenoid valves are not energized due to a power outage, etc. Also, the chuck unit can be selectively connected to the valve unit at a first rotation position and a second rotation position which have different angles around the central axis of the valve unit, and the connection relationship between the two solenoid valves and the two pressure chambers can be switched, so that it is possible to easily prevent the workpiece from falling depending on the gripping form of the workpiece. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a front view of the air chuck according to the embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the air chuck of FIG. [Diagram 3] 3 is a cross-sectional view of the air chuck taken along line III-III in FIG. 1. [Figure 4] 4 is a cross-sectional view of the air chuck taken along line IV-IV in FIG. 2. [Diagram 5] 2 is an exploded view of some components of the air chuck in FIG. 1 as viewed from a specific direction. [Figure 6] 6 is a partial exploded view of the air chuck in FIG. 1, seen from a different direction than in FIG. 5. [Figure 7] 2 is a fluid circuit diagram of the air chuck of FIG. 1 when the chuck unit is connected to the valve unit at a first rotation position. FIG. [Figure 8] 2 is a fluid circuit diagram of the air chuck of FIG. 1 when the chuck unit is connected to the valve unit at a second rotational position. FIG. [Figure 9] This shows the air chuck in Figure 1 with a waterproof cover attached. [Figure 10] 1. FIG. 4 is a diagram showing a state in which a connection state of a chuck unit with respect to a valve unit is changed in the air chuck of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The air chuck according to the present invention will be described with reference to the attached drawings, showing a preferred embodiment. In the following description, when words related to the up and down directions are used, they refer to the directions on the drawings for convenience, and do not limit the actual arrangement of each component. The air chuck 10 of this embodiment is composed of a chuck unit 12 and a valve unit 56.

[0012] (Configuration of chuck unit 12) As shown in Figures 1 and 2, the chuck unit 12 includes a rectangular parallelepiped cylinder body 14, a disk-shaped connector body 36 connected to the lower side of the cylinder body 14, a base body 42 connected to the upper side of the cylinder body 14, and a pair of fingers 50 for gripping a workpiece.

[0013] As shown in Fig. 3, a cylinder bore 14a that is open at both ends is formed in the cylinder body 14, and a piston 16 is disposed within the cylinder bore 14a. The piston 16 is composed of a main body portion 16a that slides within the cylinder bore 14a, and a rod portion 16b that extends upward from the main body portion 16a. A rod cover 22 is attached to the upper opening of the cylinder bore 14a, and a cap 24 is attached to the lower opening of the cylinder bore 14a.

[0014] A first pressure chamber 26 is formed between the main body 16a of the piston 16 and the cap 24, and a second pressure chamber 28 is formed between the main body 16a of the piston 16 and the rod cover 22. The cylinder body 14 is provided with a first pressure chamber air flow path 30 communicating with the first pressure chamber 26 and a second pressure chamber air flow path 32 communicating with the second pressure chamber 28. The first pressure chamber air flow path 30 and the second pressure chamber air flow path 32 open to the lower end of the cylinder body 14.

[0015] Two sensor grooves 14b extending from the upper end to the lower end of the cylinder body 14 are provided on the wide side surface of the cylinder body 14 (see FIG. 5). Magnetic sensors 34 that detect the magnetic field of the magnet 18 attached to the piston 16 are attached in these sensor grooves 14b, making it possible to detect the position of the piston 16. Lead wires 34a of the magnetic sensors 34 extend downward from the cylinder body 14.

[0016] A pair of L-shaped levers 44 are disposed on the base body 42. The levers 44 have a first end 44a bifurcated by a notched groove and a spherical second end 44b, and are rotatably supported at their center by a lever shaft 46 fixed to the base body 42. The first end 44a of the lever 44 engages with an engagement pin 20 provided on the rod portion 16b of the piston 16.

[0017] A support member 48 is provided on the upper side of the base body 42 to support a pair of fingers 50. The support member 48 is provided with a pair of rail grooves 48a that guide the fingers 50 in a direction perpendicular to the axis of the cylinder hole 14a. The fingers 50 have a base 50a disposed between the pair of rail grooves 48a of the support member 48, and a finger portion 50b extending upward from the base 50a. A plurality of rolling elements 49 are disposed between the base 50a of the fingers 50 and the rail groove 48a of the support member 48. The second end 44b of the lever 44 engages with an engagement groove 50c provided in the base 50a of the fingers 50. Note that reference numeral 55a denotes a bolt for connecting the base body 42 to the cylinder body 14, and reference numeral 55b denotes a bolt for connecting the support member 48 to the base body 42.

[0018] When air is supplied to the first pressure chamber 26 and air is exhausted from the second pressure chamber 28, the piston 16 is driven upward, the pair of levers 44 rotate so that the second ends 44b move away from each other, and the pair of fingers 50 move in an opening direction. When air is supplied to the second pressure chamber 28 and air is exhausted from the first pressure chamber 26, the piston 16 is driven downward, the pair of levers 44 rotate so that the second ends 44b move closer to each other, and the pair of fingers 50 move in a closing direction.

[0019] The connector body 36 is provided with a first connection passage 38 and a second connection passage 40 which penetrate vertically. The first connection passage 38 is connected to the first pressure chamber air flow path 30 of the cylinder body 14, and the second connection passage 40 is connected to the second pressure chamber air flow path 32 of the cylinder body 14. In addition, the connector body 36 is provided with a lead wire insertion hole 36a which penetrates vertically and through which the lead wire 34a of the magnetic sensor 34 is inserted.

[0020] The first bolt 52 is inserted into a first bolt insertion hole 36b provided in the connector body 36 and screwed into a screw hole 14c provided in the bottom of the cylinder body 14, thereby connecting the connector body 36 to the cylinder body 14 (see FIG. 4). Reference numerals 94a and 94b denote a pin and a pin hole used for positioning when connecting the connector body 36 to the cylinder body 14.

[0021] 5, a total of four second bolt insertion holes 36c are provided near the outer periphery of the connector body 36. The second bolt insertion holes 36c are provided at intervals of 90 degrees around the central axis CL of the connector body 36 and at positions that are not covered by the cylinder body 14 when the connector body 36 is connected to the cylinder body 14.

[0022] (Configuration of valve unit 56) 5 and 6, the valve unit 56 includes a valve unit main body 62 to which the first solenoid valve 58 and the second solenoid valve 60 are attached, and a disk-shaped adapter 92 connected to the lower side of the valve unit main body 62. The valve unit main body 62 has a cylindrical outer wall portion 64, a flow path block portion 70 provided inside the outer wall portion 64, an upper plate portion 88 provided inside the outer wall portion 64 so as to cross the flow path block portion 70, and a lower plate portion 90 provided below the flow path block portion 70. The adapter 92 is a member for attachment to a robot arm (not shown) or the like.

[0023] The outer wall portion 64 is provided with a rectangular first opening 64a, and a second opening 64b at a position opposite to the first opening 64a across the central axis CL of the valve unit 56 (the same as the central axis CL of the connector body 36). The flow path block portion 70 has a flat solenoid valve joint surface 72 facing the first opening 64a. The first solenoid valve 58 and the second solenoid valve 60 are attached to this solenoid valve joint surface 72 and are detachable through the first opening 64a.

[0024] The flow path block section 70 is provided with a first output air flow path 74 and a second output air flow path 76. One end of the first output air flow path 74 opens to the upper surface of the flow path block section 70, and the other end opens to the solenoid valve connecting surface 72. Similarly, one end of the second output air flow path 76 opens to the upper surface of the flow path block section 70, and the other end opens to the solenoid valve connecting surface 72. Note that the openings of the first output air flow path 74 and the second output air flow path 76 at the solenoid valve connecting surface 72 are omitted in Fig. 5. Reference numeral 73 denotes screw holes for mounting the first solenoid valve 58 and the second solenoid valve 60.

[0025] As will be described later, one end of the first output air flow path 74 is connected to one of the first connecting passage 38 and the second connecting passage 40 of the connector body 36, and one end of the second output air flow path 76 is connected to the other of the first connecting passage 38 and the second connecting passage 40 of the connector body 36. Fig. 3 shows a state when the first output air flow path 74 is connected to the first connecting passage 38, and the second output air flow path 76 is connected to the second connecting passage 40.

[0026] The flow path block section 70 is provided with a supply air flow path 78 consisting of a common flow path 78a, a first branch flow path 78b, and a second branch flow path 78c (see FIG. 7). One end of the common flow path 78a opens to a side surface of the flow path block section 70 located opposite the solenoid valve joint surface 72, and a supply port 66 is attached thereto (see FIG. 6). The first branch flow path 78b and the second branch flow path 78c branch off from the common flow path 78a and open to the solenoid valve joint surface 72. Air is supplied to the supply port 66 from an air supply source (not shown). Note that in FIG. 5, the openings of the first branch flow path 78b and the second branch flow path 78c at the solenoid valve joint surface 72 are omitted.

[0027] Further, the flow path block section 70 is provided with a first exhaust air flow path 80 and a second exhaust air flow path 82. One end of the first exhaust air flow path 80 opens to the solenoid valve joint surface 72, and the other end opens to the side surface of the flow path block section 70 at a position facing the second opening 64b. Similarly, one end of the second exhaust air flow path 82 opens to the solenoid valve joint surface 72, and the other end opens to the side surface of the flow path block section 70 at a position facing the second opening 64b. A first exhaust port 84 equipped with a variable throttle valve is connected to the other end of the first exhaust air flow path 80, and a second exhaust port 86 equipped with a variable throttle valve is connected to the other end of the second exhaust air flow path 82 (see FIG. 4). Note that in FIG. 5, the openings of the first exhaust air flow path 80 and the second exhaust air flow path 82 at the solenoid valve joint surface 72 are omitted.

[0028] 7, the first solenoid valve 58 and the second solenoid valve 60 are configured as a two-position three-port switching valve. The first port 58a of the first solenoid valve 58 is connected to the first output air flow path 74, the second port 58b of the first solenoid valve 58 is connected to the first branch flow path 78b of the supply air flow path 78, and the third port 58c of the first solenoid valve 58 is connected to the first exhaust air flow path 80. Similarly, the first port 60a of the second solenoid valve 60 is connected to the second output air flow path 76, the second port 60b of the second solenoid valve 60 is connected to the second branch flow path 78c of the supply air flow path 78, and the third port 60c of the second solenoid valve 60 is connected to the second exhaust air flow path 82.

[0029] The first solenoid valve 58 connects the first port 58a to the second port 58b when energized, and connects the first port 58a to the third port 58c when de-energized. In other words, the first solenoid valve 58 is a normally-closed solenoid valve that connects the first output air flow path 74 to the air supply source when energized, and opens the first output air flow path 74 to the atmosphere when de-energized.

[0030] On the other hand, the second solenoid valve 60 connects the first port 60a to the third port 60c when energized, and connects the first port 60a to the second port 60b when de-energized. In other words, the second solenoid valve 60 is a normally open type solenoid valve that opens the second output air flow path 76 to the atmosphere when energized, and connects the second output air flow path 76 to the air supply source when de-energized.

[0031] An electric connector 68 is provided on the outer wall portion 64 adjacent to the supply port 66. A lead wire 58d for supplying power to the first solenoid valve 58 and a lead wire 60d for supplying power to the second solenoid valve 60 are connected to the electric connector 68. In addition, the lead wire 34a of the magnetic sensor 34 extending downward from an opening 88a provided in the upper plate portion 88 is also connected to the electric connector 68. Note that reference numeral 95 denotes a bolt for connecting the adapter 92 to the valve unit body 62.

[0032] 9, a cylindrical waterproof cover 98 that covers the first opening 64a can be attached to the cylindrical outer wall portion 64 of the valve unit body 62. The first solenoid valve 58, the second solenoid valve 60, etc. can be protected by the waterproof cover 98. The waterproof cover 98 is provided with an opening 98a so as not to cover the first exhaust port 84 and the second exhaust port 86.

[0033] (Connection configuration between chuck unit 12 and valve unit 56) 5, the upper plate portion 88 of the valve unit body 62 is provided with a total of four second bolt mounting holes 88b at positions adjacent to the outer wall portion 64. The second bolt mounting holes 88b are provided at intervals of 90 degrees around the central axis CL of the valve unit 56. The second bolts 54 are inserted from the upper side of the connector body 36 of the chuck unit 12 into the second bolt insertion holes 36c of the connector body 36 and screwed into the second bolt mounting holes 88b of the upper plate portion 88, thereby connecting the connector body 36 to the valve unit body 62. In other words, the chuck unit 12 is connected to the valve unit 56 by the four second bolts 54.

[0034] The chuck unit 12 can be connected to the valve unit 56 at two positions that are 180 degrees apart around the central axis CL of the valve unit 56 (see FIG. 10). Hereinafter, these positions will be referred to as a "first rotation position" and a "second rotation position." In this embodiment, the chuck unit 12 is connected to the valve unit 56 by four second bolts 54 arranged at 90 degree intervals, but other connecting means may be used as long as the chuck unit 12 can be connected to the valve unit 56 at positions that are 180 degrees apart. Reference numerals 96a and 96b denote pins and pin holes used for positioning when connecting the connector body 36 to the valve unit main body 62.

[0035] In the first rotation position, the first output air flow passage 74 of the flow passage block portion 70 of the valve unit body 62 is connected to the first connection passage 38 of the connector body 36 of the chuck unit 12, and the second output air flow passage 76 of the flow passage block portion 70 of the valve unit body 62 is connected to the second connection passage 40 of the connector body 36 of the chuck unit 12 (see FIG. 7). In the second rotation position, the first output air flow passage 74 of the flow passage block portion 70 of the valve unit body 62 is connected to the second connection passage 40 of the connector body 36 of the chuck unit 12, and the second output air flow passage 76 of the flow passage block portion 70 of the valve unit body 62 is connected to the first connection passage 38 of the connector body 36 of the chuck unit 12 (see FIG. 8).

[0036] (When connected in the first rotation position) The operation of the air chuck 10 when the chuck unit 12 is connected to the valve unit 56 at the first rotation position will be described with reference to Fig. 7. The fluid circuit diagram in Fig. 7 shows a state in which the first solenoid valve 58 and the second solenoid valve 60 are not energized. In Fig. 7, reference character P1 indicates a connection point between the first output air flow path 74 and the first connecting passage 38, and reference character P2 indicates a connection point between the second output air flow path 76 and the second connecting passage 40.

[0037] When the pair of fingers 50 are biased in the opening direction, current is applied to the first solenoid valve 58 and the second solenoid valve 60. When current is applied to the first solenoid valve 58, air from the supply port 66 passes through a supply air flow path 78 of the flow path block portion 70 to the second port 58b of the first solenoid valve 58, passes from the first port 58a of the first solenoid valve 58 to the first output air flow path 74 of the flow path block portion 70, and further passes through the first connecting passage 38 of the connector body 36 and the first pressure chamber air flow path 30 of the cylinder body 14 to be supplied to the first pressure chamber 26.

[0038] In addition, when the second solenoid valve 60 is energized, the air in the second pressure chamber 28 passes through the second pressure chamber air flow passage 32 of the cylinder body 14, the second connection passage 40 of the connector body 36, and the second output air flow passage 76 of the flow passage block portion 70, reaches the first port 60a of the second solenoid valve 60, and is exhausted from the second exhaust port 86 through the second exhaust air flow passage 82 from the third port 60c of the second solenoid valve 60. Therefore, air is supplied to the first pressure chamber 26 and the air in the second pressure chamber 28 is exhausted, so that the pair of fingers 50 are driven in the opening direction. Since the second exhaust port 86 is provided with a variable throttle valve, the speed at which the pair of fingers 50 move in the opening direction can be adjusted.

[0039] When biasing the pair of fingers 50 in the closing direction, power supply to the first solenoid valve 58 and the second solenoid valve 60 is stopped. By stopping power supply to the second solenoid valve 60, air from the supply port 66 passes through the supply air flow path 78 of the flow path block portion 70 to the second port 60b of the second solenoid valve 60, passes from the first port 60a of the second solenoid valve 60 to the second output air flow path 76 of the flow path block portion 70, and further passes through the second connection passage 40 of the connector body 36 and the second pressure chamber air flow path 32 of the cylinder body 14 to be supplied to the second pressure chamber 28.

[0040] Also, by stopping the supply of electricity to the first solenoid valve 58, the air in the first pressure chamber 26 passes through the first pressure chamber air flow passage 30 of the cylinder body 14, the first connection passage 38 of the connector body 36, and the first output air flow passage 74 of the flow passage block portion 70, reaches the first port 58a of the first solenoid valve 58, and is exhausted from the first exhaust port 84 through the first exhaust air flow passage 80 from the third port 58c of the first solenoid valve 58. Therefore, air is supplied to the second pressure chamber 28 and the air in the first pressure chamber 26 is exhausted, so that the pair of fingers 50 are driven in the closing direction. Since the first exhaust port 84 is provided with a variable throttle valve, the speed at which the pair of fingers 50 move in the closing direction can be adjusted.

[0041] The air chuck 10 is attached to a robot arm (not shown) or the like with the fingers 50 facing downward. When gripping a workpiece by sandwiching the workpiece between the inner sides of the pair of fingers 50, the chuck unit 12 may be connected to the valve unit 56 at the first rotation position as described above. When electricity is not applied due to a power outage or the like, the pair of fingers 50 are driven in the closing direction, thereby preventing the workpiece from falling.

[0042] (When connected in the second rotation position) Next, the operation of the air chuck 10 when the chuck unit 12 is connected to the valve unit 56 at the second rotation position will be described with reference to Fig. 8. The fluid circuit diagram in Fig. 8 shows a state in which the first solenoid valve 58 and the second solenoid valve 60 are not energized. In Fig. 8, reference character P3 indicates a connection point between the second output air flow path 76 and the first connecting passage 38, and reference character P4 indicates a connection point between the first output air flow path 74 and the second connecting passage 40.

[0043] When the pair of fingers 50 are biased in the opening direction, the supply of electricity to the first solenoid valve 58 and the second solenoid valve 60 is stopped. By stopping the supply of electricity to the second solenoid valve 60, air from the supply port 66 passes through the supply air flow path 78 of the flow path block portion 70 to the second port 60b of the second solenoid valve 60, passes from the first port 60a of the second solenoid valve 60 to the second output air flow path 76 of the flow path block portion 70, and further passes through the first connection passage 38 of the connector body 36 and the first pressure chamber air flow path 30 of the cylinder body 14 to be supplied to the first pressure chamber 26.

[0044] Furthermore, by stopping the supply of electricity to the first solenoid valve 58, the air in the second pressure chamber 28 passes through the second pressure chamber air flow passage 32 of the cylinder body 14, the second connection passage 40 of the connector body 36, and the first output air flow passage 74 of the flow passage block portion 70, reaches the first port 58a of the first solenoid valve 58, and is exhausted from the first exhaust port 84 through the first exhaust air flow passage 80 from the third port 58c of the first solenoid valve 58. Therefore, air is supplied to the first pressure chamber 26 and the air in the second pressure chamber 28 is exhausted, so that the pair of fingers 50 are driven in the opening direction. Since the first exhaust port 84 is provided with a variable throttle valve, the speed at which the pair of fingers 50 move in the opening direction can be adjusted.

[0045] When the pair of fingers 50 are biased in the closing direction, current is applied to the first solenoid valve 58 and the second solenoid valve 60. When current is applied to the first solenoid valve 58, air from the supply port 66 passes through the supply air flow path 78 of the flow path block portion 70 to the second port 58b of the first solenoid valve 58, passes from the first port 58a of the first solenoid valve 58 to the first output air flow path 74 of the flow path block portion 70, and further passes through the second connection passage 40 of the connector body 36 and the second pressure chamber air flow path 32 of the cylinder body 14 to be supplied to the second pressure chamber 28.

[0046] In addition, when the second solenoid valve 60 is energized, the air in the first pressure chamber 26 passes through the first pressure chamber air flow passage 30 of the cylinder body 14, the first connection passage 38 of the connector body 36, and the second output air flow passage 76 of the flow passage block portion 70, reaches the first port 60a of the second solenoid valve 60, and is exhausted from the second exhaust port 86 through the second exhaust air flow passage 82 from the third port 60c of the second solenoid valve 60. Therefore, air is supplied to the second pressure chamber 28 and the air in the first pressure chamber 26 is exhausted, so that the pair of fingers 50 are driven in the closing direction. Since the second exhaust port 86 is provided with a variable throttle valve, the speed at which the pair of fingers 50 move in the closing direction can be adjusted.

[0047] The air chuck 10 is attached to a robot arm (not shown) or the like with the fingers 50 facing downward. When the pair of fingers 50 are expanded to grip a workpiece with their outer sides, the chuck unit 12 may be connected to the valve unit 56 in the second rotation position as described above. When electricity is not applied due to a power outage or the like, the pair of fingers 50 are driven in the opening direction, thereby preventing the workpiece from falling.

[0048] According to the air chuck 10 of this embodiment, the first solenoid valve 58 and the second solenoid valve 60 are a combination of a normally closed type and a normally open type, so that it is possible to prevent the workpiece from falling when the first solenoid valve 58 and the second solenoid valve 60 are not energized due to a power outage or the like. In addition, the chuck unit 12 can be selectively connected to the valve unit 56 at a first rotation position and a second rotation position which have different angles around the central axis CL of the valve unit 56, and the connection relationship between the first solenoid valve 58 and the second solenoid valve 60 and the first pressure chamber 26 and the second pressure chamber 28 can be switched, so that it is possible to easily prevent the workpiece from falling according to the gripping form of the workpiece.

[0049] In this embodiment, the air chuck 10 is configured to have a pair of fingers 50 (two fingers 50), but it may also be configured to have three or more fingers, such as when multiple fingers are arranged at equal angles on the same circumference when viewed from a specified direction.

[0050] The air chuck according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0051] 10...Air chuck 12...Chuck unit 16: piston; 26: first pressure chamber 28... second pressure chamber 34... magnetic sensor 34a, 58d, 60d...Lead wire 36...Connector body 50...Finger 56...Valve unit 58...First solenoid valve 60...Second solenoid valve 62: Valve unit body 64: Outer wall 64a...first opening (opening) 66...supply port 68...electrical connector 74...first output air flow path 76...Second output air passage 84...First exhaust port 86...Second exhaust port 98...Waterproof cover

Claims

1. An air chuck comprising a chuck unit having a plurality of fingers and a valve unit attached to a robot arm or the like, the chuck unit includes a first pressure chamber and a second pressure chamber provided on either side of a piston that drives the plurality of fingers, the valve unit includes a first output air flow passage connected to one of the first pressure chamber and the second pressure chamber, a second output air flow passage connected to the other of the first pressure chamber and the second pressure chamber, a first solenoid valve connected to the first output air flow passage, and a second solenoid valve connected to the second output air flow passage, the first solenoid valve connects the first output air flow passage to an air supply source when energized and opens the first output air flow passage to the atmosphere when not energized, and the second solenoid valve opens the second output air flow passage to the atmosphere when energized and connects the second output air flow passage to the air supply source when not energized, the chuck unit is selectively connectable to the valve unit at a first rotation position and a second rotation position which have different angles around a central axis of the valve unit, and at the first rotation position, the first output air flow path is connected to the first pressure chamber and the second output air flow path is connected to the second pressure chamber, and at the second rotation position, the first output air flow path is connected to the second pressure chamber and the second output air flow path is connected to the first pressure chamber.

2. 2. The air chuck according to claim 1, an air chuck, wherein the valve unit includes a single supply port, a first exhaust port equipped with a variable throttle valve, and a second exhaust port equipped with a variable throttle valve, the supply port being connected to the first solenoid valve and the second solenoid valve via predetermined flow paths, the first exhaust port being connected to the first solenoid valve via a predetermined flow path, and the second exhaust port being connected to the second solenoid valve via a predetermined flow path.

3. 2. The air chuck according to claim 1, The valve unit includes a valve unit body having a cylindrical outer wall portion, and the chuck unit is an air chuck including a disk-shaped connector body connected to the valve unit body.

4. 4. The air chuck according to claim 3, The first solenoid valve and the second solenoid valve are attached to the valve unit body, and an opening is provided in the outer wall portion of the valve unit body to enable the first solenoid valve and the second solenoid valve to be attached and detached.

5. 5. The air chuck according to claim 4, The valve unit body is provided with a cylindrical waterproof cover that covers the opening.

6. 4. The air chuck according to claim 3, The chuck unit is an air chuck including a magnetic sensor that detects a position of the piston, and an electrical connector to which lead wires of the magnetic sensor, lead wires of the first solenoid valve, and lead wires of the second solenoid valve are connected is provided on the outer wall portion of the valve unit body.

Images