EP0281329A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mold clamping device
Assignee: Nissei Plastic Industrial Co Ltd
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Filing: 1988-02-26
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Granted: —
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Expires: 2008-02-26
Abstract
Abstract A mold clamping device includes a clamping ram (30), whose front end is connected to a movable board (20) of an injection molding machine, and which is slidably fitted in a clamping cylinder (28). A support cylinder (29) is provided in parallel to the clamping cylinder (28). A support piston (34) is slidable in the support cylinder, and is connected to the movable board (20). A front chamber (A) and a rear chamber (B) of the clamping cylinder (separated by a piston section of the clamping ram) and a front chamber (E) of the support cylinder are connected by an oil path (36) controlled by valve means (37,38). The effective pressure receiving area of the rear chamber (B) of the clamping cylinder is substantially equal to the sum of the effective pressure receiving area of the front chamber (A) of the clamping cylinder and the front chamber (E) of the support cylinder.
Inventors
- 👤 Minoru Nissei Jushi Kogyo Kabushiki Kaisha Takada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:30
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/64; B29C45/67; B29C45/6764; B29C45/6771
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
210 words
A mold clamping device comprising: a clamping cylinder (28) slidably fitted with a clamping ram (30) whose front end is intended to be connected to a movable element (20) of a mould assembly (20,21,23-25); a high-speed piston (31) being slidably fitted in said cavity of the clamping ram (30) from the rear thereof; a support cylinder (29) which is provided in parallel to said clamping cylinder (28), and a support piston (34) fitted therein, said piston (34) dividing the cavity of the support cylinder (29) into front (E) and rear chambers, and having a rod (46) whose front end is intended to be connected to said movable element (20); there being an oil path (36) connecting said front chamber (A) and rear chamber (B) of said clamping cylinder (28) and said front chamber (E) of said support cylinder (29); a means (37,38) being provided for opening and closing said oil path (36) to said rear chamber (B) of said clamping cylinder (28); wherein the sum of the effective pressure receiving area of said front chamber (A) of said clamping cylinder (28) and said front chamber (E) of said support cylinder (29) is substantially equal to the effective pressure receiving area of said rear chamber (B) of said clamping cylinder (28).
Claim 2
Dependent Claim
210 words
A mold clamping device comprising: a clamping cylinder (28) slidably fitted with a clamping ram (30) whose front end is intended to be connected to a movable element (20) of a mould assembly (20,21,23-25); a high-speed piston (31) being slidably fitted in said cavity of the clamping ram (30) from the rear thereof; a support cylinder (29) which is provided in parallel to said clamping cylinder (28), and a support piston (34) fitted therein, said piston (34) dividing the cavity of the support cylinder (29) into front (E) and rear chambers, and having a rod (46) whose front end is intended to be connected to said movable element (20); there being an oil path (36) connecting said front chamber (A) and rear chamber (B) of said clamping cylinder (28) and said front chamber (E) of said support cylinder (29); a means (37,38) being provided for opening and closing said oil path (36) to said rear chamber (B) of said clamping cylinder (28); wherein the sum of the effective pressure receiving area of said front chamber (A) of said clamping cylinder (28) and said front chamber (E) of said support cylinder (29) is substantially equal to the effective pressure receiving area of said rear chamber (B) of said clamping cylinder (28).
Claim 3
Dependent Claim
64 words
A mold clamping device according to claim 1 wherein, said clamping cylinder (28) ans said support cylinder (29) are formed in one body as a cylinder block, and the oil path (36) connecting said front (A) and rear (B) chambers of said clamping cylinder (28) and said front chamber (E) of said support cylinder (29) is bored in the wall of said cylinder block.
Claim 4
Dependent Claim
125 words
A mold clamping device according to claim 1 wherein said oil path is provided by a connecting through-hole (47) in the piston section of said clamping ram connecting the front chamber (A) and a rear chamber (B) of said clamping cylinder (28), and an oil path (48) connecting the front chamber (E) of said support cylinder (29) to said front chamber (A) of said clamping cylinder; and said opening and closing means comprises a valve member (51) displaceably mounted on the rear of said clamping ram (30); and wherein a further chamber (H) is defined between the valve member (51) and the ram (30), and a through-hole (54) in said clamping ram connects said chamber (H) to said second chamber (D) of said clamping ram.
Claim 5
Dependent Claim
75 words
A mold clamping device according to claim 3 wherein said rear of the ram (30) has a portion of relatively large diameter and a rearward portion of relatively small diameter; said valve member (51) comprising a ring piston having portions slidably engaging said large and small diameter portions; said ring piston (51) being slidable to open and close the through-hole (47) which connects the front (A) and rear (B) chambers of the clamping cylinder (28).
Claim 6
Dependent Claim
24 words
A mold clamping device according to any preceding claim wherein, said means for opening and closing said oil path (36) is a switching valve.
Claim 7
Dependent Claim
71 words
A mold clamping device according to any preceding claim wherein said front chamber (A) of said clamping cylinder (28) or said front chamber (E) of said support cylinder (29) is connected to an oil tank (45) via a spring-check valve (43) which releases oil to the oil tank (45) and via a check valve, which is provided in parallel to said spring-check valve, for sucking oil from the oil tank (45).
Claim 8
Dependent Claim
29 words
A mold clamping device according to any preceding claim wherein the piston section of said clamping ram (30) is provided at the rear end of said clamping ram (30).
Claim 9
Dependent Claim
30 words
A mold clamping device according to any preceding claim wherein the high-speed piston 31 is fixed at its rear end to an inner rear wall of said clamping cylinder (28).
Claim 10
Dependent Claim
85 words
A mold clamping device according to any preceding claim wherein the cavity of said clamping ram (30) is divided into a front chamber (J) opening to the atmosphere and a rear chamber (D) by a large-diameter piston section provided at the front end of said high-speed piston (34) and a piston rod (62) extending from an inner wall face of said front chamber of said clamping ram is slidably fitted in said high-speed piston (31) to form a third chamber (C) in said high-speed piston.
Claim 11
Dependent Claim
118 words
A mold clamping device according to any of claims 1 to 8 wherein, the inner space of said clamping ram (30) is divided into a first chamber (C) and a second chamber (D) by a large-diameter piston section provided at the front end of said high-speed piston (31); said first chamber (C) being connected to an oil pressure source via an oil path (32) bored through said high-speed piston, and said second chamber (D) being connected to said oil pressure source via an oil path (33) having one end opened at the rear end of said high-speed piston and the other end on the outer face of said high-speed piston in said second chamber of said clamping ram.
Claim 12
Dependent Claim
131 words
A mold clamping device according to claim 10 wherein, said oil path connected to said second chamber (D) of said clamping ram is also connected to said first chamber (C) via a connecting path (57,58,60), and a valve element (59), which is slidably fitted in a large-diameter section (58) of said connecting path, serves for shutting said oil path to said second chamber (D) of said clamping ram under the influence of oil pressure in said first chamber (C) when oil is introduced into said first chamber (C) for mold closure; and for opening said oil path to said second chamber (D) and shutting said connecting path under the influence of oil pressure in said second chamber (D) when oil is introduced into said second chamber (D) for opening the mold.
Claim 13
Dependent Claim
52 words
A mold clamping device according to any preceding claim wherein, the internal diameter of the rear section of said clamping cylinder is larger than the internal diameter of the front section thereof, and the inner diameter of the front section is formed to fit the piston section of said clamping ram slidably.
Claim 14
Dependent Claim
92 words
A mold clamping device according to any preceding claim wherein, a plurality of clamping cylinders (28) are provided, and each front chamber (A) of each clamping cylinder is connected to said front chamber (E) of said support cylinder (29), and the total effective pressure receiving area of the rear chambers (B) of said clamping cylinders is substantially equal to the sum of the total effective pressure receiving area of the front chambers (A) of said clamping cylinders and the effective pressure receiving area of said front chamber (E) of said support cylinder.
References Cited (Backward Citations)
No citation records indexed.
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