JPH033530B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a closed forging device for forming connecting rods, gears, etc. of engines, compressors, etc.

(Prior Art) For example, there is a dedicated forging press shown in FIG. 7 as a closed forging device for oblong objects such as connecting rods.

In FIG. 7, reference numeral 1 denotes a lower frame, and above the lower frame 1, a main cylinder 2 is vertically opposed to each other, and both are connected by a plurality of columns 3.

A main ram 4 is slidably fitted into the main cylinder 2, and the main ram 4 is connected to the main cylinder 2.
When liquid pressure is supplied from liquid feeding ports 5 and 6 formed in the respective parts, the parts are slid in the vertical direction.

An upper mold 7 is fixed to the lower end surface of the main ram 4, a cylinder portion 8 is formed in the upper mold 7, and a piston 3 is slidably fitted into the cylinder portion 8.

Furthermore, a connecting rod and punches 10, 11, 12 for forming the large end and the small end are attached to the piston 9.

A cylinder portion 13 is formed in the main ram 4,
A punch pushing ram 14 is fitted into the cylinder portion 13, and the lower end surface of the ram 14 is attached to the center of the upper surface of the piston 9.

Note that the ram 14 is slid in the vertical direction by being supplied with hydraulic pressure from the liquid feeding ports 15 and 16.

A lower mold 18 is fixed to the lower frame 1 via a die holder 17, and the lower mold 18 has fixed punches 19, corresponding to the punches 10, 11, and 12 described above.
20 and 21 are attached, and a knockout mechanism for the molded product 22 is also provided.

(Problem to be solved by the invention) In the conventional example shown in FIG.
The material is supplied to each molding section of 8, and the molds are clamped by the downward movement of the main ram 4 to close the upper and lower molds 7, 18, and by moving the piston 9 downward, each punch 1 is
0, 11, and 12 can be pressed and filled with material in a direction perpendicular to the pressing direction to perform closed forging.

However, since each punch 10, 11, 12 is driven by the same drive mechanism, ie, the piston 9, the pushing strokes are all the same.

Therefore, it becomes impossible to independently absorb changes in the volume of the material in each section in the longitudinal direction.
Depending on the location, lack of thickness may occur, and conversely, overloading of the push punches 10, 11, and 12 may cause burrs or breakage of the punches.

In addition, the equipment was expensive because it required a dedicated press.

(Means for Solving the Problem) The present invention solves the problems of the conventional example, and by independently performing the strokes of a plurality of indentation punches, the material is sufficiently deposited into the mold impression. In addition, by changing the back-up pressure of the punches, the pushing force of each punch can be adjusted.
A feature of the present invention is that an upper mold is attached to the lower end side of the main ram which can move up and down, a lower mold corresponding to the upper mold is attached to the lower frame side, and the upper and lower molds are In a closed forging device that can be tightened and opened freely, a cylinder is removably fixed to the lower end surface of the main ram, an upper mold is removably fixed to the lower end surface of the cylinder, and a plurality of molds are installed in the cylinder. Pistons are provided to be able to move up and down, a punch that penetrates the upper mold is protruded from the lower surface of each piston, and a hydraulic oil supply device is provided in the cylinder to independently move each piston up and down. is at the point where it is connected.

(Function) According to the present invention, since the cylinder and the upper mold are removable, various combinations of the cylinder and the upper mold can be made when changing the mold, and a small number of cylinders and the upper mold can be prepared. This makes it possible to handle a wide variety of products.

Now, in order to perform closed forging, the main ram is raised to open the upper and lower dies, and the material for the object to be forged, such as a connecting rod or gear, is placed in the lower dies. supply

Next, by lowering the main ram and performing a mold clamping operation, the upper mold is lowered, and the mold is brought into close contact with the lower mold to roughly process the material.

Thereafter, by supplying pressure oil to the pushing side of each piston using the hydraulic oil supply device, the punches protruding from the lower surface of each piston penetrate the upper mold and descend, and are individually pushed into the material. Forging is performed by refilling the missing material with individual punches to prevent underfilling.

(Example) Referring to FIG. 1, a plurality of columns 31 are erected in parallel to each other on the lower frame 30, and a liquid supply port 32 for pressurization and a liquid supply port 33 for pressurization release are provided at the upper part of the column 31. A main cylinder 34 is connected thereto.

A main ram 35 is oil-tightly fitted into the main cylinder 34 and is slidable in the vertical direction.

A punch pushing cylinder 36 is removably attached to the lower end surface of the main ram 35 via a bolt (not shown), and the cylinder 36 has a pushing liquid feeding port 37 and a pushing releasing liquid feeding port 38, respectively. has been done.

Furthermore, a piston 39 is oil-tightly fitted into the cylinder 36 and is slidable in the vertical direction.The piston 39 has a molded product, in this example, a punch for forging a connecting portion of a connecting rod 40 of an engine, compressor, etc. 4
1 is installed.

Furthermore, the piston 39 has cylinder parts 42 and 43.
are formed independently, and the cylinder parts 42 and 43 are provided with punches 4 for forging the large end and the small end, respectively.
Pistons formed at the tops of 4 and 45 are fitted.

Therefore, each of the punches 41, 44, 45 can be moved up and down hydraulically with independent strokes.

Further, the upper surface of the upper mold 46 is detachably attached to the cylinder 36 via a bolt (not shown).
The punches 41 and 4 described above are attached to the molding part of the upper mold 46.
4 and 45 are protruded and inserted into the upper mold 46.

A die holder 47 is detachably attached to the lower frame 30, and a lower mold 48 is detachably attached to the die holder 47.
8 are inserted with punches 49, 50, 51 having shapes corresponding to the punches 41, 44, 45 described above,
Each punch 49, 50, 51 projects into the molding portion of the lower mold 48.

FIG. 3 shows details of the hydraulic oil supply device that supplies hydraulic oil to the cylinder 36.

In FIG. 3, a relief valve 53 and a direction switching control valve 54 are provided in the liquid sending oil path of the pump 52.
Each oil passage from the control valve 54 has a check valve 55,
56 are provided.

The oil sent from the check valve 55 is sent to a pressure increasing mechanism 57,
Liquid feed port 3 of cylinder 36 via flow rate control valve 58
7 can be pumped.

Further, the liquid sending oil from the check valve 56 is independently communicated with the liquid feeding ports 42A, 43A of each cylinder portion 42, 43 formed in the piston 39 and the liquid feeding port 38 for pushing and releasing the cylinder 36. .

That is, the cylinder portion 42 includes a relief valve 60 with a check valve 59 and a flow control valve 6 with a check valve 61.
2 to the punch 44 so as to be able to apply backup pressure.

Further, the cylinder portion 43 is connected to the punch 45 through a relief valve 64 with a check valve 63 and a flow control valve 66 with a check valve 65 so as to be able to apply backup pressure to the punch 45.

Further, the liquid supply port 38 is communicated with through a relief valve 68 with a check valve 67 and a flow control valve 70 with a check valve 69.

Referring to FIG. 2, a second embodiment of the invention is shown.

In this second embodiment, the punches 41, 44, 45 are independent cylinder parts 41A, 42, 43, respectively.
is formed.

That is, the cylinder part 41A is formed so that its center coincides with the pressurizing center, and cylinder parts 42 and 43 are formed independently on both sides of this cylinder 41A, and each punch 41, 44, 45 is formed independently. It can be moved up and down using hydraulic pressure with a stroke.

In the second embodiment shown in FIG. 2, members common to those in the first embodiment shown in FIG. 1 are indicated by common symbols.

In the third embodiment shown in FIG. 4, a punch pushing cylinder having the same structure as the first embodiment is provided for each punch 49, 50, 51 in the lower mold part. They are each operable independently, and the third embodiment is more effective than the first embodiment in that it is possible to replenish and refill the missing material from above and below.

In addition, in the third embodiment shown in FIG. 4, the hydraulic control circuit and other members of the upper mold part and the lower mold part are the same as in the first embodiment (including the example shown in FIG. 3), Common parts are indicated by common symbols.

The fourth embodiment shown in FIG.
6 shows the punch pushing cylinder mechanism.

That is, this is an example in which the piston 44A for the punch 44 is eccentrically fitted to the piston 45A for the punch 45, and this is omitted for the punch in the center.

This is because in the case of a connecting rod, since the volumes on both sides are different, it is more convenient than providing a punch in the center.

The embodiment shown in FIG. 6 schematically shows the overall configuration of the hydraulic control circuit, and includes an upper mold in which a hydraulic cylinder mechanism capable of operating a plurality of punches with independent strokes is built into the lower end surface of the main ram 35. 46 and a lower mold 48 having a punch vertically corresponding to the punch described above are formed into a die set structure, and are detachably assembled into the main ram 35 and the lower frame 30, and a hydraulic power source for the main ram 35 is provided. This allows the cylinder mechanism for pushing the punch to operate.

In the illustrated example, a pressure increasing mechanism 57 consisting of a cylinder 57A and a piston 57B is provided in an oil path to the liquid feeding port 37 for the push-in cylinder mechanism.

Note that the pushing cylinder mechanism herein means the cylinder mechanism for the movable punch in each of the embodiments described above.

Hydraulic pressure control for the main ram 35 is carried out by a direction switching control valve 72 provided in the liquid sending oil path of the punch 52 via a relief valve 71, and a check valve 73 provided in each oil path from the control valve 72. ,74
It is also clear from the figure that the driving source for the pushing cylinder mechanism is a common pump.

In addition, in FIG. 6, members common to each of the previously described embodiments are given common symbols, and
The pressure increasing mechanism 57 shown in FIG. 3 has the same configuration as the pressure increasing mechanism 57 shown in FIG.

Next, an example of the operation of the closed forging procedure will be explained.

With the upper mold 46 and the lower mold 48 opened, a material 40 such as an object to be forged, such as a connecting rod or a gear, is supplied to the forming section of the lower mold 48.

Next, the hydraulic pressure from the pump 52 is sent to the main cylinder 34 to lower the main ram 35 and perform a mold clamping operation, whereby the upper mold 46 in which the push cylinder mechanism is incorporated is lowered, and the upper mold 46 is brought into contact with the lower mold 48. In cooperation, the molds are brought into close contact and the material 40 is roughly machined.

Thereafter, by supplying pressure oil from the pump 52 to the pushing sides of the punches 41, 44, 45, which are operated with independent strokes, the punches 41, 44, 45 are individually pushed into the upper die 46. In rare cases, replace the missing material with individual punches 41, 44, 4.
In step 5, forging is performed by replenishing and filling to prevent underfilling.

In the embodiment shown in FIG. 4, a plurality of upper and lower punches 41, 44, 45, 49,
By pushing the material 40 from above and below with 50 and 51, forging can be carried out more reliably and precisely without burrs or lack of thickness.

Furthermore, as shown in FIG. 3, relief valves 60 and 6 are installed in the return lines to the tank when the punch is pushed in, respectively.
4 and 68, the punch back-up pressure can be freely changed, and the relationship between the upper mold holding force F ₀ and the punch push-in forces FP ₁ , FP ₂ , and FP ₃ can be freely changed. Can be done.

That is, F ₀ = P ₁ (AC ₁ − AP ₁ − AP ₂ − AP ₃ ) FP ₁ = P ₀ (AC ₁ − AC ₂ − AC ₃ ) − P ₁ (AC ₁ − AP ₁ −
AP ₂ − AP ₃ ) + P ₂ (AC ₃ − AP ₂ ) + P ₃ (AC ₃ −
AP ₃ ) FP ₂ = P ₀ AC ₂ −P ₂ (AC ₂ − AP ₂ ) FP ₃ = P ₀ AC ₃ −P ₃ (AC ₃ − AP ₃ ) However, AC ₁ ; Punch 41 pushing piston area AC ₂ ; Punch 44 pushing piston area AC ₃ ; Punch 45 pushing piston area AP ₁ ; Punch 41 punching area AP ₂ ; Punch 44 punching area AP ₃ ; Punch 45 punching area F ₀ ; Upper die pushing force FP ₁ ; Push-in force FP of punch ₄₁ ; Push-in force FP ₃ of punch 44; Push-in force P ₀ of punch 45; Punch pushing cylinder oil pressure P ₁ ; Back-up oil pressure P ₂ of punch 41; Back-up oil pressure P ₃ of punch 44; Backup pressure of 45 As is clear here, punchbackup pressure
By increasing P ₁ , the upper die pressing force F ₀ can be increased, and the punch pushing force FP ₁ can be decreased.

In addition, in the embodiment shown in FIG. 3 or FIG. 6, the punch pushing force can be applied with the hydraulic oil whose pressure has been increased to more than the punch discharge pressure by the pressure increasing mechanism 57, and the punch pushing force can be applied to the upper and lower molds. High-precision forging is achieved by assembling a pressure increase mechanism 57 at a suitable location separately from the die set.

In addition, after forging, each punch 41, 44, 4
The product is taken out through the return operation of step 5, the opening operation of the upper and lower molds 46 and 48, and the knock-out mechanism installed in the lower mold 48 (not shown), etc., and then transported to the next process.

(Effects of the Invention) In the present invention, the cylinder is detachably attached to the lower end of the main ram, and the upper mold is detachably attached to the lower surface of the cylinder. A single function can be made multifunctional to suit a variety of products.

Moreover, since the upper mold is equipped with a plurality of punches that are hydraulically operated independently for the molding section, it is possible to independently absorb material filling and volume fluctuations in the molding section. It is possible to accurately obtain a forged product with a high yield and no flesh, and it is also possible to prevent the punch from breaking.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is an elevational sectional view of the first embodiment, FIG. 2 is an elevational sectional view of the second embodiment, and FIG. 3 is a hydraulic control circuit for the push cylinder. Explanatory drawing, FIG. 4 is an elevational sectional view of the third embodiment,
FIG. 5 is a sectional view of the upper piston portion, FIG. 6 is an explanatory diagram showing the entire hydraulic control circuit, and FIG. 7 is an elevational sectional view of a conventional example. 35... Main ram, 36... Cylinder, 46... Upper mold, 41, 44, 45... Punch (movable side), 4
8... Lower mold, 57... Pressure increase mechanism, 52... Pump.

Claims (1)

[Scope of Claims] 1. An upper mold is attached to the lower end side of the main ram which can freely move up and down, a lower mold corresponding to the upper mold is attached to the lower frame side, and the upper and lower molds are used for mold clamping. In a closed forging device in which the mold can be opened, a cylinder is removably fixed to the lower end surface of the main ram, an upper mold is removably fixed to the lower end surface of the cylinder, and a plurality of pistons are installed in the cylinder. Each piston is provided to be movable up and down, and a punch that penetrates the upper mold is protruded from the lower surface of each piston, and a hydraulic oil supply device that independently moves each piston up and down is connected to the cylinder. A closed forging device characterized by: 2. Claim 1, wherein the plurality of pistons include one piston fitted into the cylinder and another piston fitted into a cylinder portion provided in the one piston. Closed forging device as described in section. 3. Claim 1, wherein the plurality of pistons are each fitted with a plurality of cylinder parts provided in the cylinder.
Closed forging device as described in section. 4. The hydraulic oil supply device has a common hydraulic oil supply circuit for pushing each piston downward, and has an individual backup pressure circuit for applying backup pressure to each piston when each piston is lowered, and The closed forging apparatus according to claim 1, characterized in that the pressure circuit has a backup pressure adjusting means. 5. The closed forging apparatus according to claim 4, wherein the backup pressure adjusting means comprises a pressure-adjustable relief valve. 6. The closed forging device according to claim 4, wherein a pressure increasing mechanism is interposed in the hydraulic oil supply circuit of the hydraulic oil supply device.