WO2012085621A1

WO2012085621A1 - A vertical sand moulding machine

Info

Publication number: WO2012085621A1
Application number: PCT/IB2010/055990
Authority: WO
Inventors: Søren Erik KNUDSEN; Michael AXELSEN
Original assignee: Disa Industries A/S
Priority date: 2010-12-21
Filing date: 2010-12-21
Publication date: 2012-06-28
Also published as: CN103429367A; CN103429367B

Abstract

The invention pertains to a vertical sand moulding machine 2, comprising a moulding chamber 4 formed by a bottom wall 6 and an upper wall 8 provided with one or more sand filling openings 10, communicating with a sand feed system 12. The moulding chamber 4 is also delimited by two side walls, a pressure plate 14 provided with a pressure pattern 16 and connected to a movement mechanism 18, and a swingable plate 20 provided with a swing pattern 22 and mounted for translational and swivelling movement in order to open and close the moulding chamber 4, allowing the pressure plate 14 to expel the produced moulds. The sand moulding machine 2 further comprises a first device 26, which is fixed to the swingable plate 20 and is adapted to cooperate with a second device 28, which is connected to another part of the sand moulding machine 2, for swivelling the swingable plate 20.

Description

A VERTICAL SAND MOULDING MACHINE

TECHNICAL FIELD

The present invention pertains to a vertical sand moulding machine of the kind set forth in the preamble of claim 1 .

BACKGROUND OF THE INVENTION

Sand moulding machines of the above kind have been known within the art for many years. US 3,008,199 and US 4,442,882 describes examples of known vertical sand moulding machines. These sand moulding machines comprise a moulding chamber, which is formed by a bottom wall, an upper wall provided with one or more sand filling openings communicating with a sand feed system, and two side walls. The moulding chamber is also delimited by a pressure plate provided with a pressure pattern and connected to a movement mechanism and a swingable plate. The swingable plate is provided with a swing pattern and mounted for translational and swivelling movement in order to open and close the moulding chamber, thereby allowing the pressure plate to expel the produced moulds.

The general operational principle of such a vertical sand moulding machine is that sand is initially injected into the moulding chamber while the pressure plate and swingable plate are duly separated from each other. Next, the swing plate and pressure plate are moved towards each other in order to compact the sand in the moulding chamber. After this compacting step, the swingable plate is moved outwards longitudinally and then swivelled upwards in order to leave a free passage for the sand mould, which is subsequently pressed out of the moulding chamber by the pressure plate. Then the pressure plate and swingable plate are retracted to their initial positions in order to commence the working cycle again.

In the commonly known vertical sand moulding machines the swivelling movement of the swingable plate is performed by a complicated mechanism comprising a number of lever arms and cooperating pivoting joints. One such swivelling mechanism is shown in EP 1 219 830 A2, which employs a cam device. A cam is joined to a frame, which may move longitudinally with respect to the machine. The frame is in turn joined to the swingable plate. At the other end the cam is joined to a connecting rod, which is in turn jointed on its opposite end to the swingable plate. These joints of the aforementioned elements determine the swiveling of the swingable plate, thereby allowing the extraction of the sand mould. The moving frame, which is connected to the cam, is driven by interposing bars with a cylinder placed opposite to a drive cylinder for the press plate, producing a motion of the frame itself. Initially, a push of the cylinder will only cause the longitudinal displacement of the swingable plate, until the cam reaches a roller bearing, at which time, if the cylinder continues to push, the cam will begin to swivel, pushing the connecting rod and in turn the front plate, thus making the latter swing to allow the extraction of the sand mould.

This well known way of facilitating the swiveling of the swingable plate is rather complicated because it involves the cooperation of two lever arms (the rod and cam) and several joints, by which these lever arms are connected to each other and connected to the swingable plate and frame. A swiveling mechanism of this well known kind, which comprises a number of movable parts and joints, will need continuing maintenance and periodical repair of said elements, which may lead to a production stop while reparation is going on, and will therefore in addition to the already mentioned disadvantages also lead to considerable losses in the production.

SUMMARY OF THE INVENTION

It is thus an object of the present invention to provide vertical sand moulding machine which is equipped with a swiveling mechanism that is simple and reliable in function, and which requires a minimum of maintenance.

According to the present invention, the above-mentioned and other objects are fulfilled by a vertical sand moulding machine, comprising a moulding chamber formed by a bottom wall, an upper wall provided with one or more sand filling openings communicating with a sand feed system and two side walls. The moulding chamber is also formed by a pressure plate and a swingable plate. The pressure plate is provided with a pressure pattern and connected to a movement mechanism, and the swingable plate is provided with a swing pattern and mounted for translational and swivelling movement in order to open and close the moulding chamber, allowing the pressure plate to expel the produced moulds. The sand moulding machine according to the invention further comprises a first device, which is fixed to the swingable plate and is adapted to cooperate with a second device, which is connected to a stationary part of the sand moulding machine, for swivelling the swingable plate. Hereby is achieved a swivelling mechanism, which is much simpler than the ones commonly used in the art, because it only requires the cooperation, for example interaction, of two devices - a first one that is fixed to the swingable plate - and a second device that is connected to a stationary part of the sand moulding machine. Maintenance and repair is also simpler because only the two devices need to be maintained and periodically exchanged. This also leads to a considerable cost savings because during the lifetime of a vertical sand moulding machine expenses for spare parts are considerable. Hence any reduction of the need for spare parts is welcome. Additionally, since the swivelling mechanism according to the invention essentially only comprises two devices, an exchange of one or both of these when worn-down may be done easy and quickly, thereby enabling a very short stay of the production cycle during the repair. Moreover, since the swivelling mechanism is achieved by the cooperation of a first and second device, a considerable reduction in the wear of the parts of the swivelling mechanism is also achieved.

The press plate is preferably equipped with a pressure pattern mounting plate, onto which the press pattern is mounted, and the swingable plate is preferably equipped with a swing pattern mounting plate, onto which the swing pattern is mounted. Unlike the rod known in the prior art, the first devise may be fixed relative to the swingable plate, whereby there is no movable joint between the first device and the swingable plate and thereby no wear that is associated with movable joints.

Preferably, the first device is adapted to cooperate with the second device in such a way that the swivelling of the swingable plate is caused by an abutting engagement between the first and second devices.

In a preferred embodiment of a vertical sand moulding machine according the invention, the swingable plate may be hinged to a yoke, which is connected to a movement mechanism for translational movement of the yoke, by which translational movement of the yoke the swingable plate is subjected to a translational movement until the first device touches the second device, where after the translational movement of the yoke causes the swiveling of the swingable plate. Hereby is achieved in a particularly simple way the swiveling of the swingable plate, because the translational movement of the yoke is directly transformed into the swiveling movement of the swingable plate due to the mechanical interaction between the first and second device.

The movement mechanism to which the pressure plate is connected is preferably a hydraulic piston and cylinder means. However, in other embodiments the movement means could be pneumatic or electrical. Such an electrically or pneumatically driven press plate may be advantageous in smaller vertical sand moulding machines, wherein the large hydraulic machinery and hoses will take up too much space, and wherein smaller forces are needed in order to compact the sand. Similarly, the swingable plate may in another embodiment be driven by pneumatic or electrical movement means.

In another preferred embodiment of a vertical sand moulding machine according to the invention, the first device is a cam, and the second device is a roller bearing. Hereby in a very simple, yet effective, way is achieved the swiveling of the swingable plate. The surface that is adapted for touching the roller bearing is called the active surface of the cam. This active surface of the cam has a shape so formed that it causes a swiveling of the swingable plate when this surface rolls over the roller bearing. In an alternative embodiment of a vertical sand moulding machine according to the invention, the roles of the first and second devices may be switched around so that the first device is a roller bearing and the second device is a cam.

Sand deposits on the active surface of the cam may be a significant problem, because sand deposits on the active surface of the cam will act as an abrasive between the cam and the roller bearing. Thus, in a preferred embodiment of a vertical sand moulding machine according to the invention at least a major part of the active surface of the cam is facing downwards during the swiveling movement of the swingable plate. In order to achieve a uniform wear of the cam, and in order to impart a smooth or soft swiveling motion to the swingable plate during the swiveling movement, the active surface of the cam may have a shape that imparts a smooth acceleration and de- acceleration to the swingable plate during the swiveling movement. In a preferred embodiment of the invention, the second device is connected to the front of the moulding chamber, or a frame structure of the sand moulding machine. In a preferred embodiment of a vertical sand moulding machine according to the invention, the first and second device may be placed only on one side of the sand moulding machine, thereby leaving room for changing the pattern plates from the other opposite side, which in some production cycles needs to be changed several times per hour. Additionally, the placement of the first and second devices on only one side of the sand moulding machine will not have any influence on an eventual core setter, which may be mounted in the usual way on a shaft on top of the machine. Such a core setter may be turned in front of the swingable plate and before the string of sand moulds, from the same side of the machine wherein the first and second device are placed in order to deliver a core to the previous sand mould without interfering with the swingable plate or yoke to which the swingable plate is attached. Thus, the invention will according to this preferred embodiment not require any changes to the placement and operation of an eventual pattern plate changing mechanism or an eventual core setter.

Since the newly formed sand moulds which are expelled from the moulding chamber are pushed a rather great distance from the moulding chamber and beyond the outer position of the yoke, it is understood that a core setter in other embodiments could be placed differently than explained above. What is important for a successful operation of a core setter is that there is room for it to operate in order to place a core on the last sand mould which has been expelled from the moulding chamber. This core will then be squeezed between the lastly expelled sand mould and the next one which will be expelled from the sand mould, where after the cycle of placing a new core can be repeated.

In a preferred embodiment the sand moulding machine according to the invention is equipped with a core setter and/or pattern plate changing mechanism that works as explained above.

In order to facilitate an easy exchange of the first device and/or the second device when they are worn out, or when the performance of them is impaired due to wear, the first device may be releasably connected to the swingable plate, and/or the second device may be releasably connected to another part of the sand moulding machine. According to an alternative embodiment of the invention, the first device may be movably connected to the swingable plate. In another embodiment the second device may be movably connected to another part of the machine. In a further embodiment the first device may be movably connected to the swingable plate and the second device may be movably connected to another part of the machine, for example a frame or the front of the moulding chamber. Hereby the first and/or second device can be moved in such a way relative to the machine that it leaves room for the operation of a core setter arrangement also on the side of the sand moulding machine, wherein the first and second devices are placed.

BREIF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the description and the drawings. In the following, preferred embodiments of the invention are explained in more detail with reference to the drawings, wherein

Fig. 1 schematically illustrates a part of an embodiment of a sand moulding machine according to the invention,

Fig. 2 schematically illustrates a cam and roller bearing as used in an embodiment of a sand moulding machine according to the invention,

Fig. 3 schematically illustrates a cam and roller bearing as used in an embodiment of a sand moulding machine according to the invention, and

Fig. 4a-4d schematically illustrate a part of an embodiment of a sand moulding

machine according to the invention with the swingable plate in four different positions.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may however be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the invention to those skilled in the art. Like reference numerals refer to like elements throughout. Like elements will, thus, not be described in detail with respect to the description of each figure. Fig. 1 schematically shows a side-view of an embodiment of a vertical sand moulding machine 2, comprising a moulding chamber 4. The moulding chamber 4 is formed by a bottom wall 6, an upper wall 8 provided with one or more sand filling openings 10 communicating with a sand feed system 12. The moulding chamber is also delimited by two side walls (not shown). The moulding chamber 4 is furthermore formed by a pressure plate 14 provided with a pressure pattern 16, and connected to a movement mechanism 18. The illustrated moulding chamber 4 is also delimited by a swingable plate 20 provided with a swing pattern 22 and mounted for translational and swivelling movement in order to open and close the moulding chamber 4, allowing the pressure plate 14 to expel the produced moulds 24. By the translational movement of the swingable plate 20 is understood a movement that is in a direction parallel to the bars 35.

The illustrated sand moulding machine 2 further comprises a first device 26, which is connected to the swingable plate 20 and is adapted to cooperate with a second device 28, which is connected to another part of the sand moulding machine 2, for swivelling the swingable plate 20. For the sake of intelligibility of Fig. 1 , this connection for the second device 28, i.e. the way in which it is connected to the sand moulding machine 2, is not explicitly shown.

In the illustrated embodiment of a sand moulding machine 2 according to the invention, the swingable plate 20 is hinged to a yoke 30 in the hinge 32. The yoke 30 is connected to a movement mechanism 33, via the bars 35, for translational movement (i.e. in a direction parallel to the bars 35) of the yoke 30. By this

translational movement of the yoke 30 the swingable plate 20 is subjected to a translational movement until the first device 26 touches the second device 28, where after the translational movement of the yoke 30 causes the swiveling of the swingable plate 20. The movement mechanism 18, to which the pressure plate 14 is connected, is preferably a hydraulic motor 37. However, in other embodiments the movement means 18 could be pneumatically or electrically driven. Similarly, the swingable plate 20 may in another embodiment be driven by pneumatic or electrical movement means. In the illustrated embodiment both the press plate 14 and the swingable plate 20 are driven by the same motor 37. In the illustrated embodiment the first device 26 is embodied as a cam, and the second device 28 is embodied as a roller bearing. However, it is understood that in alternative embodiments the first device could be a roller bearing, and the second device could be a cam (preferably having another shape than the one depicted in Fig. 1 as the first device).

Fig. 2 schematically shows a preferred embodiment of a cam 34 and corresponding roller bearing 36. In order to increase the intelligibility of the figure, all other technical elements that are not essential in order to illustrate the technical principle have been left out. When the swingable plate 20 is moved in a direction along the longitudinal extension of the sand moulding machine 2, the movement of the swingable plate 20 is translational until the part 38 of the surface of the cam 34 engages the roller bearing 36, at which time the further translational movement of the yoke 30 causes the swingable plate 20 to be swiveled due to the engagement of the roller bearing 36 with the active surface 39 of the cam 34. This is indicated more clearly in Fig. 3, which shows a swiveled swingable plate 20. The whole active surface, i.e. the whole surface of the cam 34, which is adapted to engage the roller bearing, of the illustrated cam 34 has partially a shape as a "half Moon". Figs. 4a-4d is a schematic illustration of a part of an embodiment of a sand moulding machine 2 showing the swingable plate 20 in four different positions.

In Fig. 4a the swingable plate 20 has been moved out of the moulding chamber 4 due to the translational motion of the yoke 30, to which it is hinged in the hinge 32. The swingable plate 20 has been moved so far out of the moulding chamber 4 that the cam 34 barely engages, i.e. touches, the roller bearing 36. In the position illustrated in Fig. 4a, the swingable plate 20 is in the horizontal position. The roller bearing 36 is connected to the front part 42 of the moulding chamber 4 via the connecting element 40. In an alternative embodiment the connecting element could be attached to the frame part 44, or any other suitable fixed part of the sand moulding machine 2.

In a practical embodiment of the invention the horizontal distance between the center of the hinge 32 and the upper part of the cam 34 is preferably chosen to be

somewhere between 70 mm and 1 10 mm, such as for example 90 mm, and the vertical distance between the center of the hinge 32 and the center of the roller bearing 36 is preferably chosen to be between 120 mm and 220 mm, such as for example 170 mm. Furthermore, it may be practical to choose the vertical distance between the center of the roller bearing 36 and the bottom wall 6 of the moulding chamber 4 to be between 320 mm and 340 mm, such as for example 330 mm. In Fig. 4b and Fig. 4c the yoke 30 has been pushed further to the left, whereby the interaction of the roller bearing 36 and the active surface of the cam 34 have caused the swingable plate 20 to swivel.

In Fig. 4d the yoke 30 has been pushed as far to the left as needed in order to swivel the swingable plate 20 to the horizontal position (this is also called the outer position of the yoke). In the illustrated position the roller bearing 36 engages the outer tip part 46 of the active surface of the cam 34.

It is understood that in alternative embodiments the roller bearing 36 could be releasably attached to the sand moulding machine 2, and/or the cam 34 could be releasably attached to the swingable plate 20.

In a preferred embodiment of a sand forming machine 2 according to the invention there is only one cam 34 and corresponding roller bearing 36, which are placed at one side of the sand forming machine, thereby leaving room for changing the pattern plates 16, 22 (also not illustrated) from the other side of the sand forming machine 2. For example it may be seen in Fig. 4A that in the illustrated position of the swingable plate 20, there is room between the swingable plate 20 and the entrance of the moulding chamber for a pattern plate changing mechanism, and since the connecting element 40 for the roller bearing 36 is only placed on the side of the sand moulding machine 2, which is seen in Fig. 4A, a pattern plate 16, 22 changing mechanism may access from the other side of the sand moulding machine 2.

This placement of the cam 34 and roller bearing 36 will also not have any influence on an eventual core setter (not shown), which may be mounted in the usual way on a shaft on top of the sand moulding machine 2. Such a core setter may be turned in front of the string of sand moulds 24, from the same side of the sand moulding machine 2 wherein the cam 34 and roller bearing 36 are placed, in order to deliver a core to the last sand mould in the string without interfering with the swingable plate 20 or yoke 30, to which the swingable plate 20 is attached. Thus, according to this preferred embodiment, the invention will not require any changes to the placement and operation of an eventual pattern plate changing mechanism (not shown) or an eventual core setter (not shown), which are already in themselves known in vertical sand moulding machines. Both the core setting and changing of pattern plates 16, 22 is preferably done automatically by specialized machinery, which specialized machinery possibly forms an integrated part of the sand moulding machine 2. It is thus rather important that there is room on the opposite side of the sand moulding machine 2 - in relation to the side wherein the cam 34 and roller bearing 36 are placed - for changing pattern plates 16, 22 and for setting of cores, when needed. In alternative embodiments the connecting element 40 could be movable, e.g.

pivotable, in a plane perpendicular to the side of the sand forming machine 2, i.e. in a plane perpendicular to the paper for the embodiments shown in Fig. 4a-4d. Hereby it is achieved that there will be access for a core setter from the same side of the sand forming machine 2 wherein the roller bearing 36 and the connecting element 40 is placed. Similarly, the cam 34 could be movable, e.g. pivotable, in a plane

perpendicular to the side of the sand forming machine 2, i.e. in a plane perpendicular to the paper for the embodiments shown in Fig. 4a-4d. In yet an alternative

embodiment, the cam 34 could be movable in a direction parallel to the side of the swingable plate 20 to which it is attached.

LIST OF REFERENCE NUMBERS

In the following is given a list of reference numbers that are used in the detailed description of the invention.

2 sand moulding machine

4 moulding chamber

6 bottom wall

8 upper wall

10 sand filling openings

12 sand feeding system

14 press plate

16 pressure pattern

18 movement mechanism

20 swingable plate

22 swing pattern

24 sand moulds

26 first device

28 second device

30 yoke

32 hinge

33 movement mechanism

34 cam

35 bars connecting the yoke 30 and movement mechanism 33 36 roller bearing

37 hydraulic motor

38 part of the active surface of the cam

39 part of the active surface of the cam

40 connecting element for the roller bearing

42 front part of the moulding chamber

44 part of the frame of a sand moulding machine

46 tip part of the cam 34

Claims

1. A vertical sand moulding machine (2), comprising a moulding chamber (4) formed by a bottom wall (6), an upper wall (8) provided with one or more sand filling openings (10) communicating with a sand feed system (12), two side walls, a pressure plate (14) provided with a pressure pattern (16) and connected to a movement mechanism (18), a swingable plate (20) provided with a swing pattern (22) and mounted for translational and swivelling movement in order to open and close the moulding chamber (4), allowing the pressure plate (14) to expel the produced moulds, characterised in that the sand moulding machine (2) further comprises a first device (26) which is fixed to the swingable plate (20) and is adapted to cooperate with a second device (28), which is connected to a stationary part of the sand moulding machine (2), for swivelling the swingable plate (20).

2. A vertical sand moulding machine (2) according to claim 1 , wherein the first device (26) is adapted to cooperate with the second device (28) in such a way that the swivelling of the swingable plate (20) is caused by an abutting engagement between the first and second devices (26, 28).

3. A vertical sand moulding machine (2) according to claim 1 , wherein the swingable plate (20) is hinged (32) to a yoke (30), which is connected to a movement mechanism (33) for translational movement of the yoke (30), by which translational movement of the yoke (30) the swingable plate (20) is subjected to a translational movement until the first device (26) touches the second device (28), where after the translational movement of the yoke (30) causes the swiveling of the swingable plate (20).

4. A vertical sand moulding machine (2) according to claim 1 , 2 or 3, wherein the first device (26) is a cam (34), and the second device (28) is a roller bearing (36).

5. A vertical sand moulding machine (2) according to claim 1 , 2 or 3, wherein the first device (26) is a roller bearing (36) and the second device (28) is a cam (34).

6. A vertical sand moulding machine (2) according to claim 4, wherein at least a major part of the active surface (38, 39) of the cam (34) is facing downwards during the swiveling movement of the swingable plate (20).

7. A vertical sand moulding machine (2) according to claim 4, 5 or 6, wherein the active surface (38, 39) of the cam (34) has a shape that imparts a smooth acceleration and de-acceleration to the swingable plate (20) during its swiveling movement.

8. A vertical sand moulding machine (2) according to any of the preceding claims, wherein the first and second device (26 and 28) are only placed on one side of the sand moulding machine (2).

9. A vertical sand moulding machine (2) according to any of the preceding claims, wherein the first device (26) is releasably connected to the swingable plate (20) and/or wherein the second device (28) is releasably connected to another part of the sand moulding machine (2).

10. A vertical sand moulding machine (2) according to any of the preceding claims, wherein the first device (26) is movably connected to the swingable plate (20) and/or the second device (28) is movably connected to another part of the machine (2).

1 1 . A vertical sand moulding machine (2) according to any of the preceding claims, further comprising a pattern plate (16, 22) changing mechanism and/or a core setter.