EP0387460A1 - Apparatus for mounting and dismounting valves and for grinding valve seats - Google Patents

Abstract

Apparatus of the type comprising a support receiving the cylinder head and which is characterised in that the cylinder head support is constituted by a clamping table carried by a support frame (1) on which the said table is mounted in a rotary manner on an axis having a generally horizontal direction, the said clamping table being mobile between two lockable positions, a mounting and dismounting position in which the cylinder head has its upper surface facing upwards, and a grinding position in which, by rotation through 180 DEG , the cylinder head has its lower surface facing upwards for the purpose of grinding the valve seats, and in that the support frame (1) carries a grinding device as well as a device for mounting and dismounting the valves. The present invention concerns the reconditioning of heat engines and allows the successive operations of dismounting, grinding and reassembly to be carried out on one and the same work station without the cylinder head having to be removed from the apparatus. <IMAGE>

Description

The present invention relates to the reconditioning of heat engines and, more particularly, to the operation of grinding the valve seats. These valves are arranged through the cylinder head of the engine, their head comes to rest against a valve seat while their stem projects from the other side of the cylinder head so as to be pushed by the rocker arm against the action of the spring. valve which is held on the support cup by means of a key engaging in a groove formed in the valve stem.

When it is necessary to proceed with a rectification operation of the valve seats, the cylinder head must be dismantled, then the valves must be dismantled before carrying out the grinding operation itself, these operations obviously being followed corresponding reassembly operations.

Currently, this operation is carried out on two work stations, a station in which the disassembly or reassembly operations of the valve are carried out and a station in which the actual grinding work is carried out. To disassemble or reassemble, the cylinder head must be present with its upper side on top. It is necessary to carry out a compression operation of the spring to extract the key and one generally uses devices which are similar to clamps, one of the spouts comes to rest on the valve head while the other, in the shape of a fork, comes to rest on the spring support cup. This first disassembly (or reassembly) operation is difficult because it monopolizes the two hands of the operator and requires a relatively long labor time.

Furthermore, to proceed with the grinding operation, the cylinder head must be turned over so as to present its underside upwards, so that it is necessary to carry out an operation not only of transfer but of turning the cylinder head from the dismantling station to the grinding station and vice versa.

The present invention aims to remedy these drawbacks, and it relates to an apparatus which makes it possible to carry out on a single workstation the successive operations of disassembly, rectification and reassembly without the cylinder head being removed from the 'apparatus.

This device is of the type comprising a support receiving the cylinder head and it is in particular remarkable in that the support for the cylinder head is constituted by a clamping table carried by a support frame on which said table is rotatably mounted on a general direction axis. horizontal, said clamping table being movable between two lockable positions, an assembly-disassembly position in which the cylinder head has its upper face upwards and a rectification position in which, by turning 180 °, the cylinder head has its lower face upwards for the rectification of the valve seats and in that said support frame carries a rectification device as well as a device for mounting and dismounting the valves.

Thanks to this arrangement, the three aforementioned operations can be carried out on the device, without manipulation of the cylinder head which is simply rotated by 180 ° between the various operations.

According to another characteristic of the invention, the valve mounting-dismounting device consists of a valve head retaining arm and a spring compression piece, said retaining arm and said compression piece being arranged on either side of the clamping table and carried by a movable vertical support in horizontal and vertical translation in said support frame, its vertical translation causing the vertical movement of the retaining arm and the compression piece between a rest position and a working position and being actuated by a control member consisting of a pedal.

In the working position, the retaining arm comes to bear on the valve head and the compression piece comes to press on the cup so as to compress the spring and release the key. This operation being carried out by a foot control, the removal of the key can be carried out very easily.

Advantageously, the axis of rotation of the clamping table on the support frame can be offset in height relative to said table so that the working level is substantially the same in the two mounting-dismounting and grinding positions. , taking into account the dimensions of the cylinder head. This makes it possible to work at substantially the same height for the three successive operations.

According to one embodiment of the invention, the compression part is mounted on a horizontal arm of adjustable length, itself mounted on the vertical support formed by a vertical rod, with the possibility of height adjustment; the retaining arm is fixed as for articulation around a horizontal axis on the vertical rod, rests on a horizontal transverse bar and comprises at its end a support rod of the valve heads perpendicular to said arm and directed upwards .

According to another characteristic of the invention, the clamping table consists of a tubular bar rotatably mounted on a horizontal crosspiece of the support frame, two plates fixed to slide to said tubular bar in the vicinity of its ends and perpendicular to these, and on which is fixed sliding at least one support block which is perpendicular to said corresponding plate and whose free end carries clamping fingers parallel to said plates; the support blocks of different height are slidably attached to the corresponding plate by means of lights arranged on said plate and through which tightening screws pass; each clamping finger has an end for bearing on the cylinder head and a longitudinal slot in which slides a clamping screw and comes to bear on a bearing screw for adjusting the height of said finger.

Thanks to this arrangement, it is easy to fix engine cylinder heads of different dimensions.

According to another characteristic of the invention, a locking device, blocking the clamping table in its two positions, assembly-disassembly and rectification, consists of at least one rod passing through the tubular bar and cooperating with fitted holes in the cross member and arranged symmetrically with respect to the axis; the crosspiece has two upper holes and two lower holes and the two locking rods are each provided with a return spring and, at their end, a gripping button.

According to yet another characteristic of the invention, the compression part consists of a clamp comprising two branches adjustable in spacing on a threaded rod with opposite pitch, the spacing of the branches being locked by a wing nut.

The grinding device consists of a tool driven by an electric motor via a hose and has a rotary handle at its end adjacent to the tool, the hose being able to rotate in this handle. According to an alternative embodiment, it consists of a tool driven by an electric motor via a transmission, a reduction gear and a cardanic link.

According to other features of the invention, the clamping table comprises an adjustable tilt device; the cross member is mounted on the support frame with horizontal and vertical translation; it is carried by two tubes, each of which is slidably mounted in another tube rotatably mounted on the support frame and is locked in position by wing screws; on each side of the support frame is provided a device for tilting the cross member consisting of a system of connecting rods.

Thanks to these latter characteristics, the position of the cylinder head can be easily adapted as a function of its dimensions and, possibly, of the approval of the manipulator.

• - la figure 1 est une vue générale en perspective de l'appareil,
• - la figure 2 est une vue partielle en perspective et de côté de l'appareil en position de montage-démontage,
• - la figure 3 est une vue analogue à celle de la figure 2 mais en position de rectifiage,
• - la figure 4 est une vue partielle représentant la compression d'un ressort de soupage,
• - la figure 5 est une vue de dessus de la table de bridage en position de montage-démontage,
• - la figure 6 est une vue partielle en perspective et de face de l'appareil en position de rectifiage, et
• - la figure 7 est une vue partielle en perspective et de derrière de l'appareil,
• - la figure 8 est une vue générale en perspective de l'appareil, représentant une variante de réalisation du dispositif de rectifiage.

Other characteristics and advantages of the invention will emerge from the description which follows, given by way of illustration and in no way limiting, with reference to the attached drawings in which:

• FIG. 1 is a general perspective view of the device,
• FIG. 2 is a partial perspective and side view of the device in the assembly-disassembly position,
• FIG. 3 is a view similar to that of FIG. 2 but in the rectifying position,
• FIG. 4 is a partial view showing the compression of a valve spring,
• FIG. 5 is a top view of the clamping table in the assembly-disassembly position,
• FIG. 6 is a partial perspective and front view of the apparatus in the grinding position, and
• FIG. 7 is a partial perspective and rear view of the device,
• - Figure 8 is a general perspective view of the device, showing an alternative embodiment of the grinding device.

The apparatus shown in Figure 1 in particular comprises a support frame 1 consisting of a frame 2 resting on the ground and supporting two vertical uprights 3 held by a horizontal upper crosspiece 4. According to the invention, this support frame is provided with a device for rectifying the valve seats constituted by a cutter 5 driven by an electric motor 6 via a hose 7, as seen in particular in FIG. 6. Advantageously, this device for grinding comprises a rotary handle 8 at its end close to the cutter 5, the flexible hose rotating in this handle 8. According to an alternative embodiment visible in FIG. 8, the grinding device is driven by an electric motor connected by a transmission 71 to a reducer 72; the latter supports the tool holder or the cutter, by means of a universal joint 73, 74; between these two universal joints, a tube 75 surrounds a hexagonal rod retained by a key. On the other hand, the grinding device is provided with a brake device 76.

The support frame 1 also comprises a device for mounting and dismounting the valves essentially consisting of a vertical cylindrical rod 11 which is mounted on the support frame 1 so that it can be moved in horizontal translation parallel to the crosspiece 4; as shown in FIG. 6, this translation is obtained by means of a support piece 12 which is slidably mounted on a horizontal cylindrical axis 13 secured to the chassis 1. This vertical rod 11 supports on the one hand a retaining arm 14 valve heads and a valve spring compression piece. The compression part 15, see FIG. 2, is substantially vertical and mounted on a horizontal arm 16 of adjustable length which is fixed in rotation around the rod 11; the height of this arm 16 and, consequently, of the compression piece 15 is discreetly adjustable by means of holes 17 provided in the rod 11. A screw 18 allows fine adjustment of the height of the compression piece 15.

The retaining arm 14, FIG. 1, is fixed to articulation around a horizontal axis 19 on the rod 11 and it rests on a horizontal transverse bar 21; this retaining arm 14 has at its end a support rod 22 perpendicular to the arm 14 and directed upwards; the height of this support rod 22 relative to the bar 14 is adjusted by means of a screw 23.

As indicated above, the rod 11 is mounted to slide vertically in its support 12 and this vertical translation is controlled by means of a pedal 24, the end of which is fixed to a vertical rod 26 and which is connected to the rod 11 by via cable 25.

As can be seen in particular in Figure 7, the aforementioned vertical rod 26 is integral with a part 27 integral with the support 12 of the rod 11; it follows that the assembly-disassembly device is integral with the part 27 which constitutes a sort of carriage which is mounted to slide horizontally on two horizontal cylindrical rods 13 and 13 ′.

The apparatus according to the invention comprises a clamping table intended for fixing the cylinder heads and which is rotatably mounted on a substantially horizontal axis. As can be seen in particular in Figures 2 and 3, the clamping table consists of a horizontal tubular bar of square section 31 which is rotatably fixed on a horizontal crosspiece 32 secured to the chassis, the rotation taking place around an axis 33 which is substantially central on the crosspiece 32 but which is offset in height relative to the tubular bar 31 (see Figures 2 and 5); two plates 34 and 35 which are substantially horizontal are fixed perpendicularly to the tubular bar 31; as can be seen in particular in Figures 2, 5 and 6, the plates 34 and 35 are slidably mounted on the bar 31 and are fixed in position by means of a nut or butterfly 36; the two plates 34 and 35 are arranged on either side of the axis of rotation 33 at the ends of the tubular bar 31.

The plate 34 or 35 carries at least one support block perpendicular to its surface and adjustable in position. In the example shown, each plate has two support blocks of different height, a large support block 37 and a small support block 38; these two support blocks are mounted to slide transversely on the plate 34 or 35 which for this purpose includes lights 39 and 41 through which tightening screws 42 pass.

Each support block supports at its free end a clamping finger 43 which, in the example shown, comprises at one of its ends a small round rod 44 which is intended to come into contact with the edge of the cylinder head and a longitudinal slot in which slides a clamping screw 45 (Figure 5); as can be seen in particular in FIGS. 2 and 5, each support block has at its free end two screws, namely the aforementioned clamping screw 45 and a support screw 46 which makes it possible to adjust the height of the finger 43 depending on the dimensions of the cylinder head to be blocked so that the finger is substantially horizontal in the clamping position.

As indicated above, the whole of this clamping table is mounted for rotation about the axis 33 which is offset in height and the clamping table can take two positions obtained by turning 180 ° around the axis 33. In a first position which is shown in particular in FIGS. 2 and 5, the clamping table and consequently the cylinder head 47 are in the low position, the cylinder head having its upper face 48 with the projecting valve stems directed upwards; this position corresponds to the valve assembly-disassembly position. In a second position, shown in particular in FIGS. 3 and 6, the assembly of the clamping table and of the cylinder head 47 are in the upper position, the cylinder head 47 having its lower face 49 with the valve seats 51 upwards. .

According to the invention there is provided a device for locking the clamping table in the two aforementioned positions; in the example shown, as shown in particular in FIGS. 1 and 2, this locking device is constituted by a rod 52 passing through the tubular bar 31 and cooperating with holes arranged in the cross member 32 and arranged symmetrically with respect to the axis 33; two upper holes 53 are used for locking in the high grinding position and the two lower holes 54 are used for locking in the low mounting-dismounting position. The locking rod 52 is provided, at its end, with a sort of button 55 which facilitates gripping thereof and a spring 56 disposed on the locking rod 52 inside the tubular bar 31 and cooperating with a stop 57 disposed on the locking rod 52 ensures that this rod is held in the position of locking, that is to say in the holes 53 or 54, while a locking cam maintains the rod 52 in the retracted position when unlocking and turning the clamping table.

According to the invention, the position of the clamping table can be adjusted in horizontal translation relative to the frame 1 and in inclination. In the embodiment shown, as can be seen in particular in Figures 2 and 3, the cross member 32 on which is fixed the entire clamping table is carried by two tubes 58 which are each slidably mounted on another tube 59 mounted on the frame, the inner tubes 58 being blocked in the outer tubes 59 by means of thumb screws; in the example shown, as can be seen in particular in Figure 2, the inner tube 58 is of circular section and the outer tube 59 is of square section.

As can be seen in Figures 1 and 2, there is provided on each side of the frame 1, an inclination device constituted by two connecting rods 61 and 62 hinged one on the other; the free end of the first connecting rod 61 is hingedly mounted on the cross member 32 and the other connecting rod 62 is fixed to rotate about a horizontal axis 63 on the chassis 1. Furthermore, the outer tube 59 supporting the cross member 32 through the inner tube 58 is, in fact, also rotatably mounted on the frame 1 about the horizontal axis 63; the tube 59 has for this purpose a lug 64 articulated on the axis 63, and the pivoting of the tube 59 is achieved by a system of connecting rods 65,66.

Finally, as can be seen in particular in FIGS. 1, 2 and 7, two threaded rods 67 comprising a crank 68 are provided on each side of the chassis 1 at its upper part to adjust the horizontality of the cross member 32. These rods threaded 67 cooperate with parts 69 guided in a vertical groove in the support frame 1, and integral with the upper part of the frame, adjustable in height.

The mode of operation of the device will now be described more precisely.

The cylinder head is therefore put in place by placing its two ends on the plates 34 and 35; on each plate 34 or 35, one of the two support blocks is moved by transverse sliding on the plate thanks to the openings 39 and 41 provided therein; then the clamping finger 43 is adjusted on the upper face 48 of the cylinder head using the support screw 46 then is locked in position by screwing the clamping screw 45. Two support blocks are provided: a large support block 37 and a small support block 38; thus cylinder heads of different thickness can easily be attached.

When the cylinder head 47 is thus fixed on the clamping table, action is taken on the device for dismantling the valves (FIGS. 2 and 5). As described above, this device comprises a compression part 15 mounted on the horizontal arm 16. This compression part 15 comprises a dismantling clamp, consisting of two arms adjustable in spacing 15 ′ on a thread with an opposite thread, the spacing of the branches being locked by a wing nut. Thus the clamp can adapt to different spring diameters depending on the type of engine cylinder head to be machined.

The operator therefore presses the pedal, and as described above, the rod 11 is translated vertically; the downward movement of the rod 11 causes the retaining arm 14 to tilt upward, since the latter rests on the horizontal bar 21; simultaneously, the valve dismantling clamp 15, which has been positioned opposite the spring 71 of a valve in question, descends, compresses the spring 71 by pressing on its support cup 72 and thus releases the key 73 which consists of two half-shells and which held the valve in place (Figure 4); after removal of this key 73, the spring 71 can be removed and the valve extracted. The retaining arm 14 has the effect that, during the action of the clamp 15 on the springs, the head of the valve is kept applied on its seat. The positioning of the clamp 15 on the spring of each valve is carried out on the one hand by displacement of the rod 11 and on the other hand by modification of the length of the horizontal telescopic arm 16, the position of the latter being locked by a nut with ears.

When all the valves have been extracted, the action on the pedal 24 is released, which is returned upwards by a return spring and thus the retaining arm 14 and the compression clamp 15 are released. The latter is then neutralized by pivoting to release the clamping table, in order to turn it over 180 °. To do this, the two gripping buttons 55 are pulled in order to release the rods 52 from the lower holes 54 arranged in the cross member 32. These rods 52 being locked in the retracted position, the clamping table is pivoted 180 ° so bringing the lower surface 49 carrying the valve seats 51 upward facing operator. The clamping table is locked in this position by locking the rods 52 in the upper holes 53 of the cross member 32 (Figure 3).

The operator can then perform the grinding operation using the grinding device described above (Figure 6).

It goes without saying that, once the rectification has been carried out, the valves are raised by reversing the clamping table in the low mounting-dismounting position and by controlling the pedal 24, by means of which the operator puts the valves back in place. using the retaining arm 14 of the valve heads and the compression clamp 15 of the spring.

It goes without saying that, before these operations, the position at the clamping table can be adjusted in horizontal and vertical translation relative to the chassis 1 and in inclination.

Claims (16)

1. Apparatus for dismantling and mounting valves and for rectifying valve seats on an engine cylinder head comprising a support receiving the cylinder head, characterized in that the support for the cylinder head is constituted by a clamping table carried by a support frame (1) on which said table is rotatably mounted on an axis of generally horizontal direction, said clamping table being movable between two lockable positions, an assembly-disassembly position in which the cylinder head (47) has its upper face ( 48) upwards and a grinding position in which, by 180 ° turning, the cylinder head (47) has its underside (49) upwards for grinding the valve seats (51) and in that said support frame (1) carries a grinding device as well as a valve mounting-dismounting device. 2. Apparatus according to claim 1, characterized in that the valve assembly-disassembly device consists of a retaining arm (14) of the valve head and a compression part (15) of the spring, said retaining arm (14) and said compression part (15) being arranged on either side of the clamping table and carried by a vertical support (11) movable in horizontal and vertical translation in said support frame (1) , its vertical translation causing the vertical displacement of the retaining arm (14) and the compression part (15) between a rest position and a working position, and being actuated by a control member consisting of a pedal (24 ). 3. Apparatus according to claim 2, characterized in that the compression part (15) is mounted on a horizontal arm (16) of adjustable length itself mounted on the vertical support (11) formed of a vertical rod, with possibility of height adjustment. 4. Apparatus according to claim 2 or 3, characterized in that the retaining arm (14) is articulated about a horizontal axis (19) on the vertical rod (11), rests on a horizontal crossbar (21 ) and comprises at its end a support rod (22) of the valve heads, perpendicular to said arm (14) and directed upwards. 5. Apparatus according to any one of the preceding claims, characterized in that the clamping table consists of a tubular bar (31) rotatably mounted on a horizontal crosspiece (32) of the support frame (1), of two plates (34,35) fixed to slide to said tubular bar (31) in the vicinity of its ends and perpendicular thereto , and on which is fixed slidingly at least one support block (37,38) which is perpendicular to said corresponding plate and whose free end carries clamping fingers 43 parallel to said plates. 6. Apparatus according to claim 5, characterized in that the support blocks of different height (37,38) are slidably fixed on the corresponding plate (34,35) by means of lights (39,41) arranged on said plate (34 or 35) and through which clamping screws (42) pass. 7. Apparatus according to claim 6, characterized in that each clamping finger (43) has a bearing end (44) on the cylinder head (47) and a longitudinal slot in which slides a clamping screw (45) and comes resting on a support screw (46) for adjusting the height of said finger. 8. Apparatus according to any one of claims 5 to 7, characterized in that a locking device, blocking the clamping table in its two positions, assembly-disassembly and rectification, consists of at least one rod (52) passing through the tubular bar (31) and cooperating with holes provided in the crosspiece (32) and arranged symmetrically with respect to the axis (33). 9. Apparatus according to claim 8, characterized in that the crosspiece (32) has two upper holes (53) and two lower holes (54) and in that the two locking rods (52) are each provided with a spring (56) recall and at their end of a button (55) for gripping. 10. Apparatus according to any one of claims 2 to 9, characterized in that the compression part (15) consists of a clamp comprising two arms (15 ′) adjustable in spacing on a thread with an opposite thread, l 'spacing of the branches being locked by a wing nut. 11. Apparatus according to any one of the preceding claims, characterized in that the grinding device consists of a tool (5) driven by an electric motor (6) via a hose (7) and comprises a rotary handle (8) at its end close to the cutter (5), the flexible hose (7) being able to rotate in this handle (8). 12. Apparatus according to any one of claims 1 to 10, characterized in that the grinding device consists of a tool driven by a electric motor via a transmission (71), a reduction gear (72) and a universal joint (73,74). 13. Apparatus according to any one of the preceding claims, characterized in that the clamping table comprises an adjustable tilt device. 14. Apparatus according to any one of the preceding claims, characterized in that the crosspiece (32) is mounted on the support frame (1) in horizontal and vertical translation. 15. Apparatus according to claim 14, characterized in that the crosspiece (32) is carried by two tubes (58) each of which is slidably mounted in another tube (59) rotatably mounted on the support frame (1) and is locked in position by wing screws. 16. Apparatus according to claim 15, characterized in that on each side of the support frame (1) is provided a tilting device of the cross (32) consisting of a system of connecting rods (61,62).

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