GB1588767A

GB1588767A - Casting or moulding machines with automatic trimming devices

Info

Publication number: GB1588767A
Application number: GB4345877A
Authority: GB
Original assignee: Tokai Rika Co Ltd
Current assignee: Tokai Rika Co Ltd
Priority date: 1977-10-19
Filing date: 1977-10-19
Publication date: 1981-04-29

Description

(54) CASTING OR MOULDING MACHINES WITH AUTOMATIC TRIMMING DEVICES (71) We, KABUSHIKI-KAISHA TOKAI RIKA-DENKI-SEIsAKUsHo, a Japanese Corporation, of 1 Aza-Kamisuiri, Ohaza Shimootai, Nishibiwajimacho, Nishikasugai, Aichi, Japan, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to casting or moulding machines with automatic trimming devices.

It is customary to mould or cast products from synthetic plastics material, synthetic resin material or metal, in a moulding machine comprising at least two mould members having confronting mould surfaces which together define a mould cavity means for opening and closing said mould cavity as required and means for removing the moulded product from the mould members. The material from which the product is made is injected into the mould cavity through a passageway in one or both mould members and the product is therefore initially formed with a sprue attached thereto which the material remaining in the passage during the moulding operation. Such sprue or burrs are then trimmed and removed by means of a trimming device separate from the moulding machine, and this removal represents a separate manufacturing step, often carried out manually.

The invention therefore provides a moulding or casting machine comprising a plurality of mould members, means for moving at least one mould member to bring about a reciprocatory movement between an open position and a closed position in which confronting surfaces thereof define a mould cavity for a product having two trimmable projections thereon, means for ejecting a moulded product from one of said confronting surfaces while the mould members are in an open position, clamp means capable of receiving a moulded product so ejected and provided with two positioning apertures - to receive said pro jections respectively, means for moving said clamp means between a product receiving position between the spaced apart confronting surfaces of the mould members in the open position and a trimming posi tion, trimming means, comprising a mov able punch member co-operating with a die-surface provided on said clamp means, said trimming means being provided to trim said product while clamped in the trimming position to remove therefrom said projec tions and flash.

Conveniently, the punch member is fixedly mounted with respect to one mould member, the clamping means being fixedly mounted with respect to the other mould member, so that the contact of the punch member with a product in the clamping means in concomitant with the arrival of the mould members in their closed condi tion preparatory to the moulding of a next moulded product.

Advantageously the machine operation may be arranged so that the punch member is moved firstly into contact with the clamped product and then to continue the movement to force the product through the clamp means past the die surface to a product discharge point, said clamp means being comprised of a band or frame adapted to surround the body of the pro duct. The due surface may, of course, be provided directly on the clamp means.

In a preferred embodiment of the inven tion, the moulding or casting machine may 'comprise two mould members, a first mould member and a second mould mem ber, confronting surfaces of which together define a mould cavity, a fixed mounting portion upon which the first mould mem ber is mounted and a moveable portion upon which the rear mould member is mounted, means for bringing about mould closing and mould-opening movements of said second mould member through a pre determined length of stroke, clamp means operable to advance in a path normal to said movements to receive a product during a time at which the confronting mould surfaces are spaced apart and to retract to a trimming position, said clamp means including two positioning apertures to receive trimmable projections on said product, and a trimming device in the form of a punch member mounted upon and to one side of said second mould member to move therewith, the clamping device including a die surface co-operating with the punch device to trim the projections and flash from the product.

The preferred embodiment of the invention will now be described in detail with reference to the accompanying drawings.

It will be understood that the description is given by way of example only and not by way of limitation of the invention.

In the drawings: Figure 1 is a plan view of a machine according to the invention with mould members in an open position; Figure 2 shows the machine with mould members in a closed position and a concomitant trimming operation; Figures 3, 4 and 5 show other stages in the operation of the machine; Figures 6 and 7 show two possible variations in the trimming device; Figure 8 shows a perspective view of a product having sprue attached, together with a member of the trimming device, and Figure 9 shows a still further possible variation in a detail of the machine.

Referring to the drawings in which like parts are denoted by like reference numerals, a frame 1 of a casting machine is provided to support a plurality of guide rods 4 spanning the machine between a pair of walls 2, 3 fixed at the opposite sides on the upper surface of the frame. One wall 2 comprises a fixed portion on which a front mould 7 is mounted, and a blocklike portion 5 on which a rear mould 10 is mounted is slidably movable on the guide rods 4.

The front mould 7 and rear mould 10 are provided with mounting means 6, 9 respectively, which in turn are secured to the fixed portion 2 and movable portion 5 respectively. The mould mmbers have confronting mould surfaces 8, 11 which define a mould cavity. A passageway (not shown) communicating with said cavity is formed in the front mould 7 in the present example. Mould ejecting pins 12 are provided, their forward end faces projecting slightly from the mould surface 11, and constituting parts of said mould surface are provided in the rear mould surface 11. Said pins 12 are connected to a piston 14 of a cylinder 13 formed on the mounting means 9.

As shown in Figure 2, such a mould closing is conducted that the movable portion 5 is transferred toward the fixed position 2 so that the rear mould 10 is brought into firm contact with the front mould 7.

Molten metal is then injected from the passage into the mould cavity produced by the confronting mould surfaces 8, 11 so as to mould a product a. The movable portion 5 is then returned in the opposite direction so as to part the mould surfaces 8, 11. The product a supported on the pins 12 are carried with the rear mould. The reciprocating motion of the movable portion 5 is controlled by a hydraulic cylinder (not shown) through a predetermined stroke, and the position to which the movable portion is moved for the mould-opening action becomes the discharge position for the product .

In the preferred embodiment, a fixed frame 22 arranged at one side of the machine is mounted on the fixed portion 2 through a bracket 21 and the fixed frame 22 is provided with a product discharge guide opening 23 the axis of which is parallel with the direction of movement of the movable portion 5. The guide rods 4 on that side of the machines are also secured in the fixed frame 22. A punch 25 is aligned with the product discharge guide opening 23 of said fixed frame 22 and is mounted on a bracket 24 projecting outwardly from the movable portion 5. A piston and cylinder 26, having direction of operation normal to the direction of reciprocating motion of the movable portion 5, is mounted on the fixed frame 22, and a clamping device 28 is mounted on a piston rod 27 of the piston and cylinder 26. The device 28 moves between a position aligned with the product discharge guide opening 23 and a position immediately in front of the rear mould 10 when in its product discharge position.

The clamping device 28 is provided with a die surface (Figure 8) which closely conforms to the dimensions of the product a having two holes 32 in which two sprues b are respectively received. It will be seen that the presence of the projections b provides a positioning means whereby to guide the product a smoothly and accurately into the clamping device 28. Thus, when the punch 25 forces the product past this surface sprues b, flash and the like attached to the product are intercepted and removed. This sprue cutting action takes place as the movable portion 5 is moved to the position of mould closing action shown in Figure 1, positions of the relevant parts being arranged so that the punch 25 is aligned with the product discharge guide opening 23 and fitted into the clamping device 28.

The bracket 21, clamping device 28 (with its die surface) and the punch 25 constitute one example of a trimming press device according to the present invention actuated by the movement of the movable portion 5.

-In a variation of the trimming device the clamping device 28 is made to clamp a part of the product a and a die surface is provided by a cutting edge of the product discharge guide opening 23.

A description will now be given of the operation of the machine.

Wrhen the rear mould 10 is moved from the discharge position as shown in Figure 1 to the mould closing position, where the rear mould 10 confronts the front mould 7 to form the mould cavity, at the same time the punch 25 enters the clamping device 28 (die) to perform trimming of the product moulded in the previous sequence of operation.

In the closed position of the mould members, molten metal is introduced into the cavity to form a product a. After the product al has solidified, when the movable portion 5 is transferred to the discharge position, then the pdoduct al supported on the pins 12 is carried on the rear mould 10 to said discharge position.

While the product a is stationary at the discharge position, the piston rod 27 of the cylinder 26 is extended, the clamping device 28 which has been aligned with the product discharge guide opening 23 is transferred adjacent the product a. Thereupon, the pins 12 are extended from the mould surface 11 of the rear mould 10 by the movement of the piston 14 so as to push the product a toward the clamping device 28 (Figure 5).

Thereupon, the piston rod 27 is retracted, the product a clamped by the clamping device 28 is released from the pins 12, the product a is transferred to a position adjacent the product discharge guide opening 23 and located opposite to the punch 25, the clamping device 28 being in contact with the fixed frame 22 (Figure 1).

Thereafter, when the movable portion 5 is moved to perform the mould closing operation again (Figure 2) the punch 25 is moved in synchronism therewith to enter the clamping device 28 so as to correctly perform trimming for the cutting and removing of the sprue b on the product a (Figure 8).

If desired, the impact of the trimming action on the product may be reduced through the agency of a buffer spring 29 acting on the punch 25 from the side of the bracket 24 as shown in Figure 6, or the punch 25 may be mounted on the rod 31 of the cylinder 30, which is supported by the bracket 24, so that the trimming action caused by the mould closing movement of the movable portion 5 is facilitated by the action of the cylinder 30 as shown in Figure 7.

A further slight variation possible in the machine is shown in Figure 9. Here, the fixed frame 22 is directly fixed on and supported by the forward end f the-twall 2 through the bracket 21, and the punch 25 is fixed on and supported by the ex- tended forward end of the movable portion.

WHAT WE CLAIM IS: 1. A moulding. or casting machine comprising a plurality of mould members, means for moving at least one mould member to bring about a reciprocatory movement between an open position and a closed position in which confronting surfaces thereof define a mould cavity for a product having two trimmable projections thereon, means for ejecting a moulded product from one of said confronting surfaces while the mould members are in an open position, clamp means capable of receiving a moulded product so ejected and provided with two positioning apertures to receive said projections respectively, means for moving said clamp means between a product-receiving position between the spaced apart confronting surfaces of the mould members in the open position and a trimming position, trimming means, comprising a movable punch member co-operating with a die-surface provided on said clamp means, said trimming means being provided to trim said product while clamped in the position to remove therefrom said projections and trimming flash.

2. A machine as claimed in claim 1 wherein the punch member is fixedly mounted with respect to one mould member, the clamping means being fixedly mounted with respect to the other mould member, so that the contact of the punch member, with a product in the clamping means is concomitant with the arrival of the mould members in their closed condition preparatory to the moulding of a next moulded product.

3. A machine as claimed in claim 1 wherein means are provided to move the punch member firstly into contact with the clamped product and then to continue the movement to force the product through the clamp means past the die surface to a product discharge point, said clamp means being comprised of a band or frame adapted to surround the body of the product.

4. A moulding or casting machine comprising two mould members, a first mould member and a second mould member, confronting surfaces of which together define a mould cavity, a fixed mounting portion upon which the first mould member is mounted and a movable portion upon which the second mould member is mounted means for bring about mould-closing and mould-opening movements of said second mould member through a predetermined length of stroke, clamp means operable to

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. by the movement of the movable portion 5. -In a variation of the trimming device the clamping device 28 is made to clamp a part of the product a and a die surface is provided by a cutting edge of the product discharge guide opening 23. A description will now be given of the operation of the machine. Wrhen the rear mould 10 is moved from the discharge position as shown in Figure 1 to the mould closing position, where the rear mould 10 confronts the front mould 7 to form the mould cavity, at the same time the punch 25 enters the clamping device 28 (die) to perform trimming of the product moulded in the previous sequence of operation. In the closed position of the mould members, molten metal is introduced into the cavity to form a product a. After the product al has solidified, when the movable portion 5 is transferred to the discharge position, then the pdoduct al supported on the pins 12 is carried on the rear mould 10 to said discharge position. While the product a is stationary at the discharge position, the piston rod 27 of the cylinder 26 is extended, the clamping device 28 which has been aligned with the product discharge guide opening 23 is transferred adjacent the product a. Thereupon, the pins 12 are extended from the mould surface 11 of the rear mould 10 by the movement of the piston 14 so as to push the product a toward the clamping device 28 (Figure 5). Thereupon, the piston rod 27 is retracted, the product a clamped by the clamping device 28 is released from the pins 12, the product a is transferred to a position adjacent the product discharge guide opening 23 and located opposite to the punch 25, the clamping device 28 being in contact with the fixed frame 22 (Figure 1). Thereafter, when the movable portion 5 is moved to perform the mould closing operation again (Figure 2) the punch 25 is moved in synchronism therewith to enter the clamping device 28 so as to correctly perform trimming for the cutting and removing of the sprue b on the product a (Figure 8). If desired, the impact of the trimming action on the product may be reduced through the agency of a buffer spring 29 acting on the punch 25 from the side of the bracket 24 as shown in Figure 6, or the punch 25 may be mounted on the rod 31 of the cylinder 30, which is supported by the bracket 24, so that the trimming action caused by the mould closing movement of the movable portion 5 is facilitated by the action of the cylinder 30 as shown in Figure 7. A further slight variation possible in the machine is shown in Figure 9. Here, the fixed frame 22 is directly fixed on and supported by the forward end òf the-twall 2 through the bracket 21, and the punch 25 is fixed on and supported by the ex- tended forward end of the movable portion. WHAT WE CLAIM IS:

1. A moulding. or casting machine comprising a plurality of mould members, means for moving at least one mould member to bring about a reciprocatory movement between an open position and a closed position in which confronting surfaces thereof define a mould cavity for a product having two trimmable projections thereon, means for ejecting a moulded product from one of said confronting surfaces while the mould members are in an open position, clamp means capable of receiving a moulded product so ejected and provided with two positioning apertures to receive said projections respectively, means for moving said clamp means between a product-receiving position between the spaced apart confronting surfaces of the mould members in the open position and a trimming position, trimming means, comprising a movable punch member co-operating with a die-surface provided on said clamp means, said trimming means being provided to trim said product while clamped in the position to remove therefrom said projections and trimming flash.

advance in a path normal to said movements to receive a product during a time at.which the confronting mould surfaces are spaced apart, and to retract to a trimming position, said clamp means including twopositioning apertures to deceive trimmable projections on said product, and trimming means in the form of a punch memers mounted upon and to one side of said second mould member to move therewith, the clamping device including a die surface co-operating with the punch device to trim the projections and flash from the product.

5. A moulding or casting machine incorporating a trimming device, constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as shown in the accompanying drawings.