GB1577607A - K and others explosion - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO EXPLOSION HAMMERS (71) We, GEORGY KUZMICH STEPANTSOV of ulitsa Belinskogo 21, kv.

36, Kazan; JURY NIKOLAEVICH BLOSCHIT SYN of Yasenevo, mikraraion, 1, korpus 1, podiezd 3, kv. 141, Moscow; ALEXANDR ALEXEEVICH BABKO of ulitsa Sotsialisticheskaya 3, kv. 20, Kazan; FERDINAND KHAZIEVICH KUTLIN of ulitsa Mirnaya 61, kv. 75, Kazan; and IVAN VASILIEVICH GLAZUNOV of ulitsa Serova 35, kv. 136, Kazan; all of U.S.S.R. and all citizens of the Union of Soviet Socialist Republics, do hereby declare the invention, for which we pray that a patent may be granted 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 explosion hammers.

According to the present invention, there is provided an explosion hammer comprising a stationary bed, a load-bearing frame mounted in said stationary bed and arranged to carry a lower die, a piston mounted above the lower die for movement in a piston chamber in said load-bearing frame, the piston having a piston rod arranged to carry an upper die coaxially with the lower die, an explosion device carried by the load-bearing frame and comprising an explosion chamber defined by the portion of said chamber above the piston, an electrically-actuated igniter for igniting an explosive charge within the explosion chamber, a sleeve-like hollow casing mounted for axial adjustment and having an open bottom end which defines the upper end of the explosion chamber, the inner space of said hollow casing being communicatable with the explosion chamber and being arranged to receive an explosive charge such that the charge passes from the casing into the explosion chamber through the bottom end of the casing, and a check valve operable to close the explosion chamber after admission of the charge from the casing.

An embodiment of the invention will.now be described, by way of example only with reference to the accompanying diagrammatic drawing, the sole Figure of which is a vertical section of an explosion hammer according to the invention.

As shown in the drawing the explosion hammer comprises a stationary bed 1 which is rigidly fixed to a foundation (not shown).

The bed 1 has guides 2 in which a loadbearing frame 3 is mounted in known manner. A lower die 4 accommodating a blank S is mounted in the lower portion of the load-bearing frame 3. The upper portion of the load-bearing frame 3 has a cylindrical inner space accommodating a piston 6 which defines, within the space, an upper piston chamber 7a and a lower piston chamber 8.

The piston 6 has a piston rod 9, the free end of which carries an upper die 10. The upper die 10 is arranged coaxially with the lower die 4.

The lower piston chamber 8 communicates with a gas line 12 through a bore 11 whereby the chamber 8 can be filled with gas under pressure so that the piston 6 together with the piston rod 9 and upper die 10 are held in an initial uppermost position (as shown in the drawing). An explosion device 13 is mounted in the upper portion of the load-bearing frame 3 in such a manner that the upper piston chamber 7a also constitutes the explosion chamber of the device.

The explosion device comprises a hollow casing 14 in the form of a sleeve. The casing 14 is axially adjustable in the frame 3 by means of a thread. An open lower end of the casing 14 faces the explosion chamber 7a to define the upper end of the chamber. The open end of the casing 14 is provided with a chamfer 15 at its inner edge and the inner space or bore 16 of the casing 14 is stepped.

A portion of the bore 16 adjacent the upper end wall of the casing 14 is of a diameter which is substantially greater than the diameter of its portion adjacent the lower open end of the casing 14. The portions of greater and smaller diameters are joined by a conical surface, the included angle of which does not exceed 90".

The explosion device 13 is provided with a check valve 17 comprising a rod 18 having a conical head 19 at its lower end. The rod 18 is mounted in the bore 16 of the casing 14 coaxially therewith so that the conical surface of the head 1 9 mates with the chamfer 15. The conical surface of the head 19 and the chamfer 15 of the casing 14 are inclined at the same angle to the axis of the rod 18, and their surfaces are lapped.

A central hole is made in the upper end wall of the casing 14, and the upper end of the rod 18 extends through this hole. The rod 18 is axially movable by means of a drive 20 of any appropriate type. The drive 20 is mounted on the casing 14 as shown in the drawing.

In the lowermost position of the rod 18, an annular space 21 is formed between the conical head 19 and the chamfer 15 of the casing 14 to establish communication of the bore 16 with the explosion chamber 7a.

A through-hole 22 is made in the wall of the casing 14 adjacent the upper end wall thereof to extend tangentially to the cylindrical surface of the bore 16. The hole 22 is designed to establish communication of the bore 16 with a conduit 23 through which granular explosive, such as powder, is fed by a gas under pressure. An electric igniter 24 for igniting the explosive is incorporated in the load-bearing frame 3 to lie in the wall of the explosion chamber above the uppermost position of the piston.

The end portion of the rod 18 extending through the upper end wall of the casing 14 is formed with an axial bore 25 and a radial bore 26 in communication with each other to form a passage. The bores 25 and 26 serve to discharge to the atmosphere the gas used for feeding the explosive to the explosion chamber 7a. Also the bores 25 and 26 serve for the removal of combustion products following the explosion.

The explosion hammer described functions in the following manner.

In the initial position, the piston 6 and the piston rod 9 supporting the upper die 10 are in their uppermost position under the action of gas pressure in the lower piston chamber 8 which is in permanent communication with the air line 12.

The rod 18 is lowered by means of the drive 20 to open the check valve 17 and to form an annular space 21 between the conical head 19 of the valve 17 and the internal chamfer 15 of the casing 14. A charge of explosive is admitted to the casing bore 16 along the conduit 23 by means of gas under pressure. The stream of compressed gas with the explosive flows into the bore 16 tangentially to the cylindrical surface thereof and is swirled into a vortex flow.

The particles of explosive which are heavier than the gas are thrown by centrifugal forces against the wall of the bore 16 and fall down under gravity to enter the explosion chamber 7a through the space 21.

The gas used for feeding the explosive is discharged into atmosphere through the bores 25 and 26 provided in the end portion of the rod 18. After the charge of explosive has been admitted to the explosion chamber 7a, the drive 20 is actuated to raise the rod 18 to its uppermost position so as to close the space 21, the conical head 19 intimately engaging the chamfer 15 so that the explosion chamber 7a is sealed.

After that, a preheated blank 5 is placed in the lower die and a voltage is applied to the electric igniter 24 to ignite the charge whereby an explosion occurs. Gases formed in the chamber 7a act on the upper end of the piston 6. Under the action of gas pressure, the piston 6 and the piston rod 9 supporting the upper die 10 are caused to move towards the blank 5. The upper die 10 deforms the blank 5, whereafter the upper die 10 is stopped in its lowermost position.

The drive 20 is then reversed, and the rod 18 is lowered to open the valve 17. Combustion products leave the explosion chamber 7a and pass through the bore 16 and the bores 25 and 26 into atmosphere. The pressure in the explosion chamber 7a falls and the piston 6, the piston rod 9 and the upper die 10 are lifted to the uppermost position under the action of the gas pressure in the lower piston chamber 8 which is in permanent communication wbih the air line 12.

The forged blank is removed from the lower die 4. This completes the operational cycle.

If it is required to change the quantity of explosive in the charge, it will also be necessary to alter the volume of the explosion chamber 7a. For this purpose, the casing 14 is screwed axially in or out in the threaded hole of the lead-bearing frame 3 to increase or reduce the volume of the explosion chamber 7a, respectively.

The construction described enables the volume of the explosion chamber to be varied and the admission of granular explosive in a pre-set amount directly to the explosion chamber thus permitting variation in the amount of charge over a large range, and hence variation in the kinetic energy imparted to the upper die over a large range so as to obtain a pre-set impact energy. Thus parts of different sizes can be treated by a single hammer, whereby the manufacturing capabilities of the hammer are enlarged.

The provision of the igniter in the wall of the explosion chamber ensures positive ignition of the explosive and hence the hammer is reliable in operation.

The hammer can advantageously be used for the manufacture of a large variety of parts of different size, such as compressor and turbine blades.

WHAT WE CLAIM IS: 1. An explosion hammer comprising a stationary bed, a load-bearing frame mounted in said stationary bed and arranged to carry a lower die, a piston mounted above the lower die for movement in a piston chamber in said load-bearing frame, the piston having a piston rod arranged to carry an upper die coaxially with the lower die, an explosion device carried by the load-bearing frame and comprising an explosion chamber defined by the portion of said chamber above the piston, an electrically-actuated igniter for igniting an explosive charge within the explosion chamber, a sleeve-like hollow casing mounted for axial adjustment and having an open bottom end which defines the upper end of the explosion chamber, the inner space of said hollow casing being communicatable with the explosion chamber and being arranged to receive an explosive charge such that the charge passes from the casing into the explosion chamber through the bottom end of the casing, and a check valve operable to close the explosion chamber after admission of the charge from the casing.

2. A hammer as claimed in claim 1, wherein the check valve comprises a rod mounted in the casing and having an upper end portion extending through an aperture in an upper end wall of the casing and a conical head at its lower end, said head defining with a chamfer provided at the bottom end of the casing, an annular space to establish communication of the inner space of the casing with the explosion chamber which is closed when the rod is lifted to seat the head in engagement with the chamfer.

3. A hammer as claimed in claim 1 or claim 2, wherein the inner space of the casing communicates with a conduit for feeding granular explosive via an aperture which extends tangentially to an inner cylindrical surface of the casing, the inner space being stepped in axial section with the portion of the space adjacent the upper end of the casing being of a diameter which is substantially greater than the diameter of the portion thereof adjacent the bottom end of the casing.

4. A hammer as claimed in claim 2, or claim 2 and claim 3, wherein the upper end portion of the rod extending through the aperture in the upper end wall of the casing is formed with a passage to establish communication of the inner space of the casing with the atmosphere.

5. An explosion hammer substantially as hereinbefore described with reference to the accompanying drawing.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. explosion chamber ensures positive ignition of the explosive and hence the hammer is reliable in operation. The hammer can advantageously be used for the manufacture of a large variety of parts of different size, such as compressor and turbine blades. WHAT WE CLAIM IS:

1. An explosion hammer comprising a stationary bed, a load-bearing frame mounted in said stationary bed and arranged to carry a lower die, a piston mounted above the lower die for movement in a piston chamber in said load-bearing frame, the piston having a piston rod arranged to carry an upper die coaxially with the lower die, an explosion device carried by the load-bearing frame and comprising an explosion chamber defined by the portion of said chamber above the piston, an electrically-actuated igniter for igniting an explosive charge within the explosion chamber, a sleeve-like hollow casing mounted for axial adjustment and having an open bottom end which defines the upper end of the explosion chamber, the inner space of said hollow casing being communicatable with the explosion chamber and being arranged to receive an explosive charge such that the charge passes from the casing into the explosion chamber through the bottom end of the casing, and a check valve operable to close the explosion chamber after admission of the charge from the casing.

2. A hammer as claimed in claim 1, wherein the check valve comprises a rod mounted in the casing and having an upper end portion extending through an aperture in an upper end wall of the casing and a conical head at its lower end, said head defining with a chamfer provided at the bottom end of the casing, an annular space to establish communication of the inner space of the casing with the explosion chamber which is closed when the rod is lifted to seat the head in engagement with the chamfer.

3. A hammer as claimed in claim 1 or claim 2, wherein the inner space of the casing communicates with a conduit for feeding granular explosive via an aperture which extends tangentially to an inner cylindrical surface of the casing, the inner space being stepped in axial section with the portion of the space adjacent the upper end of the casing being of a diameter which is substantially greater than the diameter of the portion thereof adjacent the bottom end of the casing.

4. A hammer as claimed in claim 2, or claim 2 and claim 3, wherein the upper end portion of the rod extending through the aperture in the upper end wall of the casing is formed with a passage to establish communication of the inner space of the casing with the atmosphere.

5. An explosion hammer substantially as hereinbefore described with reference to the accompanying drawing.