Cap holding mechanism and capper

Abstract

To provide a mechanism capable of adsorbing a cap at a low cost without using a special device for suctioning air such as a vacuum pump, so as to more certainly resolve defective holding of the cap by enabling usage in combination with a chuck having a claw that opens / closes with a supply / exhaust of compressed air.SOLUTION: The mechanism comprises: an inner rod 23 fitted on an elevating shaft 11 inside a housing 14, in which an upper position is restricted by a stopper 21, having a packing 22 disposed on a bottom edge face; and a suction head 26 disposed such that a relative position to the inner rod 23 is variable by a first energizing member 25 interposed between itself and the inner rod 23. A vacuum pad 28 normally protruded further downward than a pad block 27 is provided on an inverted recess part of a bottom face of the pad block 27 of the suction head 26. An air passage 30 having a supply / exhaust opening 29 communicated within the vacuum pad 28, capable of being blocked by the packing 22, is formed in the pad block 27.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a cap holding mechanism for holding a cap when covering the mouth of a container and a capper.

Background Art

[0002] Conventionally, as a method for holding a cap when covering the mouth of a container by plugging or screwing, etc., a method of opening and closing a plurality of claw-shaped chucks to hold and release the outer peripheral wall of the cap has been adopted (see Patent Document 1).

[0003] A method of opening and closing the plurality of claw-shaped chucks will be described by taking an example of a capper.

[0004] The capper shown in this conventional example is a device provided in the capper area of the conveyance path of a container of a liquid filling device to perform covering by plugging on the mouth of the filled container in the conveyance path. This capper is provided with a cap chuck for gripping the cap and a cap chuck lifting mechanism for lifting and lowering the cap chuck in a direction of approaching and separating from the mouth of the container conveyed to the capper area.

[0005] The cap chuck lifting mechanism is provided with a pushing cylinder formed by an air cylinder or the like. A piston rod, a straight tubular operation shaft, and a cap chuck are sequentially connected to the lower end of this pushing cylinder. By driving the pushing cylinder, the cap chuck moves integrally in the vertical direction.

[0006] Here, the cap chuck is provided with a cylinder housing, and a large-diameter portion of the lower end of the operation shaft is fixed to the axial center portion inside the cylinder housing. Also, inside the cylinder housing, a piston block and a plurality of gripping members pressed by this piston block are provided. A hole through which the large-diameter portion of the operation shaft is inserted is formed in the axial center portion of the piston block. Further, an inclined pressing surface for pressing the gripping members in the inner diameter direction is formed on the lower surface of the piston block.

[0007] Each gripping member is provided with a claw chuck bent in a substantially L shape extending outward from an end plate fixed to the bottom of the cylinder housing, and a pressing portion connected to the upper part of this claw chuck. An inclined pressing receiving surface having a shape corresponding to the pressing surface on the lower surface of the piston block is formed on the upper surface of this pressing portion.

[0008] And, an air passage communicating with the pressure chamber in the upper part of the cylinder housing is formed at the upper end of the large-diameter portion of the operation shaft, and this air passage communicates with the inside of the tube of the operation shaft. And, an air supply port of an air pipeline for supplying compressed air for operating the cap chuck is formed at the upper end of the operation shaft. The piston block inside the cylinder housing is held at the upper position of the cylinder housing when the cap chuck is held in the open state.

[0009] And, when operating the cap chuck, operating air is supplied from the air supply port of the air pipeline through the inside of the tube of the operation shaft to the pressure chamber side in the upper part of the cylinder housing through the air passage. At this time, as the piston block moves downward, the upper surface of the pressing receiving portion of each gripping member is pressed by the inclined surface of the pressing surface of the piston block, and each gripping member moves inward. And, when the piston member moves to the lower limit position, the claw chuck of each gripping member moves to a position where it grips the outer peripheral surface of the cap, and the cap is gripped.

[0010] After that, the cap chuck that holds the cap performs an operation of pushing the held cap into the mouth of the container by driving the push cylinder of the cap chuck lifting mechanism.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0012] By the way, in a capper that holds a cap using such a claw chuck, when the contact portion between the claw chuck and the cap is worn, or the shape of the cap to be held is, for example, an unstable shape for gripping such as an inverted taper in the peripheral wall portion where the claw chuck abuts, it may not be possible to grip the cap well. When the cap comes off the claw chuck and falls outside the cap chuck, the cap may be caught in the drive mechanism of the filling device, which may interfere with the drive of the filling device itself or damage the device.

[0013] As a means for holding the cap in the capper, in addition to the method of gripping the cap using the aforementioned claw chuck, a method of adsorbing the cap using negative pressure by intake air is also widely adopted (see Patent Document 2). However, even in the holding of the cap by this adsorption, due to some factors, the cap may not be adsorbed and held, and a situation of poor holding such that the cap is dropped may occur.

[0014] Also, if it is possible to surely hold the cap by using both methods of gripping the cap by opening and closing the chuck by supplying and exhausting compressed air as described above and adsorbing and holding the cap by negative pressure due to intake air and releasing, the occurrence of poor cap holding can be more surely avoided. However, it has been technically and cost-prohibitive to provide both a device for supplying compressed air and a device for sucking air, such as a vacuum pump, which are contradictory, within the same capper.

[0015] The present invention has been made in view of such problems, and provides a mechanism capable of adsorbing a cap inexpensively without using a special device for sucking air such as a vacuum pump. Moreover, the mechanism enables combined use with a claw chuck that opens and closes by supplying and exhausting compressed air, and aims to provide a cap holding mechanism that can more surely solve the problem of poor cap holding, and a capper equipped with the same.

Means for Solving the Problems

[0016] In order to achieve the above-described object, the cap holding mechanism of the present invention is a cap holding mechanism in a cap chuck that is disposed at the lower end of a lifting shaft disposed in a capper and that approaches and separates from the mouth of a container as the lifting shaft moves up and down. The cap chuck includes cap suction means in a housing fixed by extending a vacuum pad shaft at the lower end of the lifting shaft as an axial center portion. The cap suction means includes an inner rod that is fitted onto the vacuum pad shaft in a state where the upper position is restricted by a stopper disposed on the vacuum pad shaft in the housing, and a packing is disposed on the lower end surface, and an adsorption head disposed at the tip of the vacuum pad shaft so that the relative position with the inner rod can be varied by contraction of a first biasing member interposed between the inner rod and the inner rod. The adsorption head has a cylindrical pad block, and a vacuum pad that always protrudes from an end portion of the pad block is disposed in a reverse concave portion formed on the lower surface of the axial center portion of the pad block. The pad block is formed with an air passage having an air supply / discharge opening that communicates with the inside of the vacuum pad and can be closed by the packing. When the lifting shaft descends and the vacuum pad contacts the upper surface of the cap of the container and contracts, and the air in the vacuum pad escapes from the air supply / discharge opening through the air passage, the inner rod that was always in the upper position by the stopper also descends to block the air supply / discharge opening to generate a negative pressure for adsorbing the cap. It is characterized in that it is configured as described above.

[0017] By providing this cap suction means, while lowering the lifting shaft, the air in the vacuum pad of the adsorption head that has come into contact with the upper surface of the cap of the container is removed from the air supply / discharge opening, and further, the vacuum pad is pressed against the upper surface of the cap and the packing disposed on the inner rod closes the air supply / discharge opening to generate a negative pressure in the vacuum pad, thereby enabling the cap to be adsorbed and held. To release the adsorption, the lifting shaft is raised, the inner rod is pushed up to the upper position of the stopper by the biasing force of the first biasing member, the air supply / discharge opening that was blocked by the packing is opened, and the negative pressure in the vacuum pad is released.

[0018] Furthermore, the cap holding mechanism of the present invention includes cap gripping means. The cap gripping means is fitted around the axis of the vacuum pad so as to be able to move up and down while slidingly contacting the inner wall of the housing. The inner rod and the suction head are housed in an inverted recess formed on the lower surface of the axial center portion. Normally, a chuck block held at an upper position in the housing by a second biasing member disposed between the chuck block and the block for the pad, and a plurality of gripping members pressed by the chuck block are provided. The chuck block has an inclined pressing surface formed on its lower surface for pressing the gripping members in the inner diameter direction. Each gripping member has a sliding block portion disposed in the housing and a claw portion located below the opening of the lower surface of the housing for gripping the cap. An inclined pressing receiving surface having a shape corresponding to the pressing surface of the chuck block is formed on the upper surface of the sliding block. An air passage is formed in the lifting and lowering moving shaft and the axis of the vacuum pad for supplying pressure air supplied from an air supply source into a pressure chamber formed in the upper part of the housing and exhausting the pressure air in the pressure chamber from a valve.

[0019] By providing this cap gripping means in combination with the cap suction means, pressure air is supplied from an air supply source to the pressure chamber in the housing as the lifting and lowering moving shaft descends, the chuck block is pushed downward in the housing, the pressing surface and the pressing receiving surface of the gripping member are brought into sliding contact with each other, and the gripping member is moved in the inner diameter direction to close the claw portion, thereby gripping the cap. The release of the gripping is performed by opening a valve communicating with the air passage and adjusting the amount of pressure air in the pressure chamber.

[0020] And, the capper of the present invention includes the aforementioned cap holding mechanism. The lifting and lowering moving shaft is a pushing cylinder. The lower end of the block for the pad acts as a pressing portion for transmitting the pressing force of the pushing cylinder that descends to the cap covering the mouth portion of the container.

[0021] The capper having this configuration can hold and cap the cap only by raising and lowering the lifting and lowering movement shaft during capping.

Effect of the Invention

[0022] As described above, according to the cap holding mechanism and the capper of the present invention, it is possible to configure a mechanism that can adsorb the cap at low cost without using a special device for generating negative pressure by sucking air such as a vacuum pump. Moreover, since the mechanism can be used in combination with a claw chuck that opens and closes by supplying and exhausting compressed air, the cap can be held by both methods of adsorption and gripping by the claw chuck, so that the problem of poor cap holding can be more reliably solved.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0024] The capper 1 equipped with the cap holding mechanism 10 of the present embodiment is a capper 1 that caps the mouth part of the filled container B. It is disposed at the lower end of the pushing cylinder 11 as the lifting and lowering movement shaft 11 disposed on the capper 1, and has a cap chuck 12 that comes into contact with and separates from the mouth part of the container B as the pushing cylinder 11 moves up and down.

[0025] The cap chuck 12 is provided at the lower end of the pushing cylinder 11, and is disposed in a housing 14 that extends and is fixed with a vacuum pad shaft 13 that moves up and down together with the pushing cylinder 11 at the axial center. It includes both a cap suction means 20 for sucking and holding the cap C, which constitutes the cap holding mechanism 10 of the present embodiment, and a cap gripping means 40 as a claw chuck for gripping the same cap C.

[0026] As shown in FIG. 1, the cap suction means 20 is fitted onto the vacuum pad shaft 13 with its upper position regulated by a stopper 21 disposed above the vacuum pad shaft 13 within the housing 14. An inner rod 23 is provided with a packing 22 made of urethane or the like for generating negative pressure on its lower end surface. A spring 25 as a first biasing member 25 inserted around the vacuum pad shaft 13 is interposed between the inner rod 23 and the vacuum pad shaft 13. The suction head 26 disposed at the tip of the vacuum pad 28 shaft 13 has a variable relative position with the inner rod 23 due to the contraction of the spring 25.

[0027] The suction head 26 has a cylindrical pad block 27. A bellows-shaped vacuum pad 28 made of silicon or the like, which always protrudes beyond the lower end of the pad block 27, is disposed in a reverse concave portion 27a formed on the lower surface of the axial center portion of the pad block 27 where the vacuum pad shaft 13 is arranged. As shown in FIG. 2, an air passage 30 having an air supply / discharge opening 29 formed in communication with the inside of the vacuum pad 28 and closable by the packing 22 is formed in the pad block 27.

[0028] When the push cylinder 11 descends and the vacuum pad 28 abuts against the upper surface of the cap C of the container B and contracts, causing the air in the vacuum pad 28 to escape from the air supply / discharge opening 29 through the air passage 30, the inner rod 23, which was always in the upper position by the stopper 21, also descends to close the air supply / discharge opening 29 and is adjusted to generate a negative pressure for sucking the cap C.

[0029] In addition, the cap gripping means 40 has a chuck block 41 and a plurality of gripping members 42. The chuck block 41 is fitted around the vacuum pad shaft 13 so as to be able to move up and down while sliding on the inner wall of the housing 14, and is always held at an upper position within the housing 14 by a spring 43 as a second biasing member 43 disposed between the chuck block 41 and the pad block 27. And, in the reverse recess 41b formed on the lower surface of the chuck block 41 where the vacuum pad shaft 13 is disposed, the inner rod 23 and the suction head 26 constituting the cap suction means 20 described above are housed.

[0030] Further, on the chuck block 41, an inclined pressing surface 41a for pressing the gripping member 42 in the inner diameter direction is formed on its lower surface. Each of the plurality of gripping members 42 pressed by the chuck block 41 is annularly arranged around the axis of the vacuum pad shaft 13 within the housing 14, and is always biased by a biasing member (not shown) so as to be separated radially outward from the vacuum pad shaft 13.

[0031] The gripping member 42 is composed of a sliding block 44 slidably placed on the horizontal edge portion 14a forming the opening of the housing 14, a claw portion 45 for gripping the cap C located below the opening on the lower surface of the housing 14, and a connecting portion 46 connecting the sliding block portion 44 and the claw block portion 45. On the upper surface of the sliding block portion 44, an inclined pressing receiving surface 42a having a shape corresponding to the pressing surface 41a of the chuck block 41 is formed.

[0032] And, on the large-diameter vacuum pad shaft 13 integrally connected to the push cylinder 11, a pressure air passage 48 is formed for supplying pressure air from an air supply source (not shown) into the pressure chamber 15 formed in the upper part within the housing 14, and exhausting the pressure air in the pressure chamber 15 from a valve (not shown).

[0033] Also, in the present embodiment, packing 16 is appropriately disposed between the vacuum pad shaft 13 and the inner rod 23, between the inner rod 23 and the chuck block 41, and between the chuck block 41 and the housing 14.

[0034] Next, the operation of the cap holding mechanism 10 configured as described above will be described. In the cap holding mechanism 10 of the capper 1 of the present embodiment, the cap suction means 20, as the push cylinder 11 driven by a drive source (not shown) and the vacuum pad shaft 13 descend, lowers the inner rod 23 fitted to the vacuum pad shaft 13 against the biasing force of the spring 25. At the same time, the suction head 26 that has come into contact with the upper surface of the cap C of the container B due to the descent of the vacuum pad shaft 13 discharges the air in the vacuum pad 28 from the air supply / discharge opening 29, and further presses the vacuum pad 28 strongly against the upper surface of the cap C as the vacuum pad shaft 13 descends. At this time, the packing 22 disposed on the inner rod 23 closes the air supply / discharge opening 29 to make the inside of the vacuum pad 28 a negative pressure, thereby sucking and holding the cap C.

[0035] Also, at the same time, the cap gripping means 40 supplies pressure air from the air supply source to the pressure chamber 15 in the housing 14 through the pressure air passage 48 in accordance with the descent of the push cylinder 11, and uses this pressure air to push the chuck block 41 downward in the housing 14 against the biasing force of the spring 43, and slidably contacts the pressing surface 14a and the pressure receiving surface 42a of the gripping member 42 to move the gripping member 42 in the inner diameter direction, thereby closing the claw portion 45 and gripping the cap C adsorbed and held by the cap suction means 20.

[0036] And in the capper 1 of the present embodiment, due to the further descent of the push cylinder 11, the lower end of the pad block 27 contacts the upper surface of the cap C adsorbed by the vacuum pad 28, and acts as a pressing portion that transmits the pressing force of the descending push cylinder 11 to the cap C covering the mouth portion of the container B, and the cap C is pushed into the mouth portion of the container B using the pressing force of the push cylinder 11.

[0037] In addition, to release the suction, the push cylinder 11 is raised, the inner rod 23 is pushed up by the biasing force of the spring 25 to the upper position of the stopper 21, and the air supply / discharge opening 29 blocked by the packing 22 is opened to release the negative pressure in the vacuum pad 28. Also, to release the gripping, a valve communicating with the pressure air passage is opened to reduce the amount of pressure air in the pressure chamber 15, and the chuck block 41 is pushed back upward inside the housing 14 by the biasing force of the spring 43. The sliding block portion 44 of the gripping member 42 whose pressing surface is in sliding contact with the pressing surface 41a of the chuck block 41 is pushed back in the outer diameter direction inside the housing by a biasing member (not shown) to open the claw block portion 45.

[0038] As described above, according to the cap holding mechanism 10 and the capper 1 of the present embodiment, without using a special device such as a vacuum pump to suck air and generate negative pressure, the cap C can be sucked and held and capped only by raising and lowering the push cylinder 11 during capping by the cap suction means 20. Moreover, since the cap gripping means 40 that opens and closes with the supply and discharge of compressed air is used in combination with the mechanism, and the cap C is held by both suction and gripping methods, the problem of poor holding of the cap C can be more reliably solved. In particular, in the case where the shape of the cap C is a special shape such that the peripheral wall portion is an inverted taper, etc., it is an effective countermeasure against poor holding.

[0039] Note that the cap holding mechanism 10 and the capper 1 of the present invention are not limited to the above-described embodiment, and various modifications can be made within the scope that does not impair the features of the present invention. For example, the capper 1 is not limited to a capping device.

Explanation of Reference Numerals

[0040] 1 Capper 10 Cap holding mechanism 11 Lifting and moving shaft (push cylinder) 12 Cap chuck 13 Shaft for vacuum pad 14 Housing 14a Horizontal edge 15 Pressure chamber 16 Packing 20 Cap suction means 21 Stopper 22 Packing 23 Inner rod 25 First biasing member (spring) 26 Suction head 27 Pad block 27a Reverse concave portion 28 Vacuum pad 29 Exhaust opening 30 Air passage 40 Cap gripping means 41 Chuck block 41a Pressing surface 41b Reverse concave portion 42 Gripping member 42a Pressing receiving surface 43 Second biasing member (spring) 44 Sliding block portion 45 Claw block portion 46 Connecting portion 48 Pressure air passage C Cap B Container

Claims

1. A cap holding mechanism in a cap chuck that is disposed at the lower end of a lifting and lowering movement shaft provided in a capper and that comes into contact with and separates from the mouth portion of a container as the lifting and lowering movement shaft moves up and down, comprising: The cap chuck is: equipped with cap suction means in a housing fixed by extending a vacuum pad shaft at the lower end of the lifting and lowering movement shaft to the axial center; The cap suction means is: an inner rod that is fitted onto the vacuum pad shaft in a state where its upper position is regulated by a stopper disposed on the vacuum pad shaft within the housing, and a packing is disposed on the lower end surface; a suction head disposed at the tip of the vacuum pad shaft such that the relative position with the inner rod can be varied by contraction of a first biasing member interposed between the inner rod and the suction head; and has The suction head has a cylindrical pad block, and a vacuum pad that always protrudes beyond the end of the pad block is disposed in a reverse concave portion formed on the lower surface of the axial center of the pad block. An air passage having an air supply / discharge opening formed in communication with the inside of the vacuum pad and closable by the packing is formed in the pad block. When the lifting and lowering movement shaft descends and the vacuum pad abuts against the upper surface of the cap of the container and contracts, and the air in the vacuum pad escapes from the air supply / discharge opening through the air passage, the inner rod, which was always in the upper position by the stopper, also descends to block the air supply / discharge opening and generate a negative pressure for adsorbing the cap. A cap suction mechanism characterized by this configuration.

2. The cap holding mechanism according to Claim 1, further comprising cap gripping means, The cap gripping means is: a chuck block that is fitted around the vacuum pad shaft so as to be able to move up and down while slidingly contacting the inner wall of the housing, and the inner rod and the suction head are housed in a reverse concave portion formed on the lower surface of the axial center, and is always held at an upper position within the housing by a second biasing member disposed between the chuck block and the pad block; and a plurality of gripping members pressed by the chuck block, The chuck block has an inclined pressing surface formed on its lower surface for pressing the gripping members in the inner diameter direction. Each gripping member has a sliding block portion disposed within the housing and a claw portion that grips the cap and is located below the opening on the lower surface of the housing. An inclined pressing receiving surface having a shape corresponding to the pressing surface of the chucking block is formed on the upper surface of the sliding block. The lifting and lowering movement shaft and the vacuum pad shaft are characterized in that an air passage is formed for supplying pressure air supplied from an air supply source into a pressure chamber formed in the upper part of the housing and exhausting the pressure air in the pressure chamber from a valve.

3. A capper comprising the cap holding mechanism according to claim 1 or claim 2, wherein the lifting and lowering movement shaft is a pushing cylinder, and the lower end of the pad block acts as a pressing portion that abuts against the upper surface of the cap adsorbed by the vacuum pad and transmits the pressing force of the pushing cylinder that descends to the cap covering the mouth of the container.

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