JPS642810B2 - - Google Patents
Info
- Publication number
- JPS642810B2 JPS642810B2 JP56119214A JP11921481A JPS642810B2 JP S642810 B2 JPS642810 B2 JP S642810B2 JP 56119214 A JP56119214 A JP 56119214A JP 11921481 A JP11921481 A JP 11921481A JP S642810 B2 JPS642810 B2 JP S642810B2
- Authority
- JP
- Japan
- Prior art keywords
- pilot
- hydraulic
- valve
- pipe
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000011144 upstream manufacturing Methods 0.000 claims description 3
- 239000010720 hydraulic oil Substances 0.000 description 23
- 239000003921 oil Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 239000000446 fuel Substances 0.000 description 3
- 238000010276 construction Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/04—Special measures taken in connection with the properties of the fluid
- F15B21/042—Controlling the temperature of the fluid
- F15B21/0427—Heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/30—Directional control
- F15B2211/32—Directional control characterised by the type of actuation
- F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/62—Cooling or heating means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/60—Circuit components or control therefor
- F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
- F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
Landscapes
- Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Operation Control Of Excavators (AREA)
Description
【発明の詳細な説明】
この発明はパイロツト式方向切換弁を有する油
圧回路、とくに油圧シヨベル、油圧クレーン、油
圧ブルドーサ等の土木、建設機械の油圧回路に関
するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic circuit having a pilot type directional control valve, and particularly to a hydraulic circuit for civil engineering and construction machines such as hydraulic excavators, hydraulic cranes, and hydraulic bulldozers.
第１図は従来のパイロツト式方向切換弁を有す
る油圧シヨベルの油圧回路を示す図である。図に
おいて１，２は油圧ポンプ、３，４は油圧ポンプ
１，２に接続された切換弁グループ、５，６は切
換弁グループ３，４内に設けられたリリーフ弁、
７は旋回切換弁、８はアーム切換弁、９は左走行
切換弁、１０は右走行切換弁、１１はバケツト切
換弁、１２はブーム切換弁で、切換弁７〜１２は
パイロツト式方向切換弁であり、また切換弁７〜
９、切換弁１０〜１２はそれぞれ並列に接続され
ている。１３は旋回モータ、１４はアームシリン
ダ、１５は左走行モータ、１６は右走行モータ、
１７はバケツトシリンダ、１８はブームシリンダ
で、アクチユエータ１３〜１８はそれぞれ切換弁
７〜１２に接続されている。１９はパイロツト用
油圧ポンプ、２０は油圧ポンプ１９に接続された
リリーフ弁、２１〜２３はパイロツト弁、２４は
パイロツト弁２１〜２３と切換弁７〜１２のパイ
ロツトポートとを接続するパイロツト管路Ａ〜Ｌ
をすべて総称したものである。 FIG. 1 is a diagram showing a hydraulic circuit of a hydraulic excavator having a conventional pilot type directional control valve. In the figure, 1 and 2 are hydraulic pumps, 3 and 4 are switching valve groups connected to the hydraulic pumps 1 and 2, and 5 and 6 are relief valves provided in the switching valve groups 3 and 4.
7 is a swing switching valve, 8 is an arm switching valve, 9 is a left running switching valve, 10 is a right running switching valve, 11 is a bucket switching valve, 12 is a boom switching valve, and switching valves 7 to 12 are pilot type directional switching valves. , and the switching valve 7~
9. The switching valves 10 to 12 are connected in parallel. 13 is a swing motor, 14 is an arm cylinder, 15 is a left travel motor, 16 is a right travel motor,
17 is a bucket cylinder, 18 is a boom cylinder, and actuators 13 to 18 are connected to switching valves 7 to 12, respectively. 19 is a pilot hydraulic pump, 20 is a relief valve connected to the hydraulic pump 19, 21 to 23 are pilot valves, and 24 is a pilot pipe line A connecting the pilot valves 21 to 23 and the pilot ports of the switching valves 7 to 12. ~L
It is a general term for all.
この油圧回路においては、パイロツト弁２１〜
２３を操作すれば、パイロツト管路２４にパイロ
ツト弁２１〜２３の操作量に応じたパイロツト圧
が発生し、そのパイロツト圧により切換弁７〜１
２が切換えられ、アクチユエータ１３〜１８が作
動する。 In this hydraulic circuit, pilot valves 21 to
23, pilot pressure corresponding to the amount of operation of the pilot valves 21 to 23 is generated in the pilot line 24, and this pilot pressure causes the switching valves 7 to 1 to be operated.
2 is switched, and the actuators 13 to 18 are activated.
ところで、冬期または寒冷地においては、油圧
シヨベルの稼動を開始する前の作動油の温度が低
く、パイロツト管路２４内の作動油の粘性が高い
から、パイロツト弁２１〜２３を操作したとして
も、切換弁７〜１２が全く切換わらないことがあ
り、また切換つたとしても作動遅れが生ずる。こ
のため、油圧シヨベルを稼動する前に、パイロツ
ト管路２４内の作動油の温度を上昇させる必要が
ある。 By the way, in winter or in cold regions, the temperature of the hydraulic oil is low before the hydraulic excavator starts operating, and the viscosity of the hydraulic oil in the pilot pipe line 24 is high, so even if the pilot valves 21 to 23 are operated, The switching valves 7 to 12 may not switch at all, and even if they do switch, there will be a delay in operation. Therefore, before operating the hydraulic excavator, it is necessary to raise the temperature of the hydraulic fluid in the pilot pipe line 24.
この油圧回路においてパイロツト管路２４内の
作動油の温度を上昇させるには、つぎのようにし
ている。すなわち、まずたとえばブーム切換弁１
２を切換えて、ブームシリンダ１８をストローク
エンドまで伸長し、さらにブーム切換弁１２をそ
のままの位置にしておく。すると、油圧ポンプ２
の圧油がリリーフ弁６でリリーフするから、タン
ク内の作動油の温度が上昇する。そして、タンク
内の作動油の温度が適正温度に達したのち、パイ
ロツト弁２１〜２３を操作して、油圧ポンプ１９
によりパイロツト管路２４にタンク内の作動油を
供給し、パイロツト管路２４内の作動油の温度を
上昇する。しかしながら、油圧ポンプ１９の吐出
量は油圧ポンプ１，２の吐出量に比べはるかに小
さいのが常（たとえば３分の１）であり、油圧ポ
ンプ１，２，１９の作動時において各パイロツト
管路の温度上昇も３分の１となり、また各パイロ
ツト管路２４の内の作動油の温度を上昇させるた
めには、すべてのパイロツト管路２４にタンク内
の作動油を供給する必要があるので、パイロツト
弁２１〜２３を操作しなければならず、さらにパ
イロツト管路２４内の作動油は循環しないため、
切換弁７〜１２のパイロツトポート近傍のパイロ
ツト管路２４内の作動油の温度はなかなか上昇し
ない。したがつて、パイロツト管路２４内の作動
油の温度を上昇するのに長時間を要するととも
に、この間エンジンを作動する必要があるので燃
料を多く使用しなければならない。さらに、すべ
てのパイロツト管路２４にタンク内の作動油を供
給するには、パイロツト弁２１〜２３を頻繁に操
作しなければならないので、面倒である。 In this hydraulic circuit, the temperature of the hydraulic oil in the pilot pipe 24 is raised in the following manner. That is, first, for example, the boom switching valve 1
2, the boom cylinder 18 is extended to the stroke end, and the boom switching valve 12 is left in the same position. Then, hydraulic pump 2
Since the pressure oil is relieved by the relief valve 6, the temperature of the hydraulic oil in the tank increases. After the temperature of the hydraulic oil in the tank reaches the appropriate temperature, the pilot valves 21 to 23 are operated to turn off the hydraulic pump 19.
The hydraulic oil in the tank is supplied to the pilot pipe 24, and the temperature of the hydraulic oil in the pilot pipe 24 is increased. However, the discharge amount of the hydraulic pump 19 is usually much smaller (for example, one-third) than the discharge amount of the hydraulic pumps 1 and 2, and when the hydraulic pumps 1, 2, and 19 are operated, each pilot pipe The temperature rise in the tank will also be reduced to one third, and in order to increase the temperature of the hydraulic oil in each pilot pipe 24, it is necessary to supply the hydraulic oil in the tank to all pilot pipes 24. Since the pilot valves 21 to 23 must be operated and the hydraulic oil in the pilot pipe 24 is not circulated,
The temperature of the hydraulic oil in the pilot pipe line 24 near the pilot ports of the switching valves 7 to 12 does not rise easily. Therefore, it takes a long time to raise the temperature of the hydraulic oil in the pilot pipe 24, and since it is necessary to operate the engine during this time, a large amount of fuel must be used. Furthermore, in order to supply the hydraulic oil in the tank to all the pilot lines 24, the pilot valves 21 to 23 must be operated frequently, which is troublesome.
この発明は上述の問題点を解決するためになさ
れたもので、単時間に、少ない燃料で、かつ簡単
な操作でパイロツト管路内の作動油の温度を上昇
することができる油圧回路を提供することを目的
とする。 This invention was made to solve the above-mentioned problems, and provides a hydraulic circuit that can raise the temperature of hydraulic oil in a pilot pipe in a single time, with a small amount of fuel, and with a simple operation. The purpose is to
この目的を達成するため、この発明においては
複数のパイロツト式方向切換弁を有する切換弁グ
ループと、そのパイロツト式方向切換弁を操作す
るためのパイロツト弁と、上記パイロツト弁と上
記パイロツト式方向切換弁のパイロツトポートと
を接続するパイロツト管路と、上記切換弁グルー
プからタンクに至る戻り管路に設けられた冷却器
とを備えた油圧回路において、上記戻り管路の上
記冷却器より上流側と上記パイロツト管路の上記
パイロツトポート近傍とを合流管路を介して接続
するとともに、その合流管路に開閉弁を設ける。 In order to achieve this object, the present invention provides a switching valve group having a plurality of pilot type directional control valves, a pilot valve for operating the pilot type directional control valves, the pilot valve and the pilot type directional control valve. In the hydraulic circuit, the hydraulic circuit includes a pilot pipe line connecting the pilot port of the valve and a cooler provided in the return line leading from the switching valve group to the tank, and a pilot line connected to the pilot port of the The pilot conduit is connected to the vicinity of the pilot port via a confluence conduit, and an on-off valve is provided in the confluence conduit.
第２図はこの発明に係る油圧シヨベルの油圧回
路を示す図である。図において２５は切換弁グル
ープ３，４からタンクに至る戻り管路、２６は戻
り管路２５に設けられた冷却器、２７は戻り管路
２５の冷却器２６より上流側とパイロツト管路２
４の切換弁７〜１１のパイロツトポート近傍とを
接続する合流管路で、合流管路２７の後流側は管
路イ〜ヌに分岐しており、管路イ〜ヌにはそれぞ
れパイロツト管路２４から管路イ〜ヌの分岐点に
至る流れを阻止するチエツク弁（図示せず）が設
けられている。２９は合流管路２７に設けられた
開閉弁、２８は合流管路２７の開閉弁２９より上
流側に設けられたチエツク弁である。 FIG. 2 is a diagram showing a hydraulic circuit of a hydraulic excavator according to the present invention. In the figure, 25 is a return pipe leading from the switching valve groups 3 and 4 to the tank, 26 is a cooler provided in the return pipe 25, and 27 is a link between the return pipe 25 upstream of the cooler 26 and the pilot pipe 2.
This confluence pipe connects the vicinity of the pilot port of the switching valves 7 to 11 of No. 4, and the downstream side of the confluence conduit 27 branches into conduits I to N, and each conduit I to N has a pilot pipe. A check valve (not shown) is provided to prevent flow from line 24 to the junction of lines I--N. Reference numeral 29 indicates an on-off valve provided in the confluence pipe 27, and 28 indicates a check valve provided upstream of the on-off valve 29 in the confluence pipe 27.
この油圧回路においては、ブーム切換弁１２を
切換えて、ブームシリンダ１８をストロークエン
ドまで伸長し、さらにブーム切換弁１２をそのま
まの位置にしておくとともに、開閉弁２９を開に
すると、油圧ポンプ２の圧油がリリーフ弁６でリ
リーフするから、戻り管路２５内の作動油の温度
が上昇するが、冷却器２６における流路抵抗は大
きいので、冷却器２６により戻り管路２５内に圧
力が発生するから、温度が上昇した戻り管路２５
内の作動油は合流管路２７を介してパイロツト管
路２４の切換弁７〜１１のパイロツトポート近傍
に流入しパイロツト管路２４、パイロツト弁２１
〜２３、パイロツト弁２１〜２３のタンク管路３
０を経てタンクに戻るから、パイロツト管路２４
内の作動油の温度が上昇する。そして、パイロツ
ト管路２４内の作動油の温度が適正温度に達した
のちに、開閉弁２９を閉にすれば、パイロツト弁
２１〜２３を操作することにより、切換弁７〜１
２を切換えることができる。 In this hydraulic circuit, the boom switching valve 12 is switched to extend the boom cylinder 18 to the stroke end, and the boom switching valve 12 is left in the same position and the on-off valve 29 is opened. Since the pressure oil is relieved by the relief valve 6, the temperature of the hydraulic oil in the return pipe 25 increases, but since the flow resistance in the cooler 26 is large, pressure is generated in the return pipe 25 by the cooler 26. Therefore, the temperature of the return pipe 25 has increased.
The hydraulic oil in the pilot pipe 24 flows into the vicinity of the pilot ports of the switching valves 7 to 11 of the pilot pipe 24 through the confluence pipe 27, and then flows into the pilot pipe 24 and the pilot valve 21.
~23, tank pipe line 3 of pilot valves 21~23
Since it returns to the tank via 0, the pilot pipe 24
The temperature of the hydraulic fluid in the tank rises. If the on-off valve 29 is closed after the temperature of the hydraulic oil in the pilot pipe line 24 reaches the appropriate temperature, the switching valves 7 to 1 can be opened by operating the pilot valves 21 to 23.
2 can be switched.
なお、上述実施例においては、油圧シヨベルの
油圧回路について説明したが、油圧クレーン、油
圧ブルドーザ等の土木、建設機械の油圧回路にこ
の発明を適用できることは当然であ。また、上述
実施例においては、ブーム切換弁１２を切換えて
油圧ポンプ２の圧油をリリーフしたが、アーム切
換弁８等を切換えることにより、油圧ポンプ１２
の圧油をリリーフしてもよい。 In the above embodiments, the hydraulic circuit of a hydraulic excavator has been described, but it goes without saying that the present invention can be applied to hydraulic circuits of civil engineering and construction machines such as hydraulic cranes and hydraulic bulldozers. Further, in the above embodiment, the pressure oil of the hydraulic pump 2 is relieved by switching the boom switching valve 12, but by switching the arm switching valve 8 etc., the pressure oil of the hydraulic pump 12 is relieved.
Pressure oil may be relieved.
以上説明したように、この発明に係る油圧回路
においてはタンク内の作動油の温度を上昇すると
同時に、温度が上昇した作動油をパイロツト管路
に供給するから、タンク内の作動油の温度が適正
温度になつたときには、パイロツト管路内の作動
油の温度が適正温度になるので、非常に短時間
に、かつ少ない燃料で、パイロツト管路内の作動
油の温度を適正温度にすることができる。また、
温度が上昇した作動油をパイロツト管路内に供給
するのに、パイロツト弁を頻繁に操作する必要が
なく、開閉弁を切換えるだけでよいから、非常に
簡単な操作でパイロツト管路内の温度を適正温度
にすることができる。このように、この発明の効
果は顕著である。 As explained above, in the hydraulic circuit according to the present invention, the temperature of the hydraulic oil in the tank is increased, and at the same time, the heated hydraulic oil is supplied to the pilot pipe, so that the temperature of the hydraulic oil in the tank is maintained at an appropriate level. When the temperature is reached, the temperature of the hydraulic oil in the pilot line reaches the appropriate temperature, so it is possible to bring the temperature of the hydraulic oil in the pilot line to the appropriate temperature in a very short time and with a small amount of fuel. . Also,
There is no need to operate the pilot valve frequently to supply heated hydraulic oil into the pilot pipe, and it is only necessary to switch the on-off valve, so it is possible to control the temperature in the pilot pipe with a very simple operation. The temperature can be adjusted to the appropriate temperature. As described above, the effects of this invention are remarkable.
第１図は従来の油圧シヨベルの油圧回路を示す
図、第２図はこの発明に係る油圧シヨベルの油圧
回路を示す図である。
１，２……油圧ポンプ、３，４……切換弁グル
ープ、５，６……リリーフ弁、７〜１２……切換
弁、１３〜１８……アクチユエータ、１９……パ
イロツト用油圧ポンプ、２１〜２３……パイロツ
ト弁、２４……パイロツト管路、２５……戻り管
路、２７……合流管路、２９……開閉弁。
FIG. 1 is a diagram showing a hydraulic circuit of a conventional hydraulic excavator, and FIG. 2 is a diagram showing a hydraulic circuit of a hydraulic excavator according to the present invention. 1, 2... Hydraulic pump, 3, 4... Switching valve group, 5, 6... Relief valve, 7-12... Switching valve, 13-18... Actuator, 19... Hydraulic pump for pilot, 21- 23... Pilot valve, 24... Pilot pipe line, 25... Return pipe line, 27... Merging pipe line, 29... Opening/closing valve.
Claims (1)
弁グループと、そのパイロツト式方向切換弁を操
作するためのパイロツト弁と、上記パイロツト弁
と上記パイロツト式方向切換弁のパイロツトポー
トとを接続するパイロツト管路と、上記切換弁グ
ループからタンクに至る戻り管路に設けられた冷
却器とを具えた油圧回路において、上記戻り管路
の上記冷却器より上流側と上記パイロツト管路の
上記パイロツトポート近傍とを合流管路を介して
接続するとともに、その合流管路に開閉弁を設け
たことを特徴とする油圧回路。1. A switching valve group having a plurality of pilot type directional switching valves, a pilot valve for operating the pilot type directional switching valve, and a pilot pipe connecting the pilot valve and the pilot port of the pilot type directional switching valve. and a cooler provided in a return line leading from the switching valve group to the tank, the upstream side of the return line from the cooler and the vicinity of the pilot port of the pilot line. A hydraulic circuit characterized in that it is connected via a merging pipe and is provided with an on-off valve in the merging pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56119214A JPS5821006A (en) | 1981-07-31 | 1981-07-31 | Hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56119214A JPS5821006A (en) | 1981-07-31 | 1981-07-31 | Hydraulic circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5821006A JPS5821006A (en) | 1983-02-07 |
| JPS642810B2 true JPS642810B2 (en) | 1989-01-18 |
Family
ID=14755761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56119214A Granted JPS5821006A (en) | 1981-07-31 | 1981-07-31 | Hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5821006A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3272788B1 (en) | 2016-07-22 | 2020-07-08 | Ricoh Company, Ltd. | Resin powder for solid freeform fabrication, device for solid freeform fabrication object, and method of manufacturing solid freeform fabrication object |
| WO2020213586A1 (en) | 2019-04-16 | 2020-10-22 | コニカミノルタ株式会社 | Resin powder for three-dimensional molding, three-dimensional molded article, and method for producing three-dimensional molded article |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6119110U (en) * | 1984-07-09 | 1986-02-04 | 株式会社神戸製鋼所 | Hydraulic operating circuit |
| JPS6122903U (en) * | 1984-07-13 | 1986-02-10 | 株式会社神戸製鋼所 | Hydraulic operating circuit |
| JPS6176874A (en) * | 1984-09-21 | 1986-04-19 | トリニテイ工業株式会社 | Hot-air circulating furnace |
| JPS61126183U (en) * | 1985-01-25 | 1986-08-08 | ||
| JPS62110006A (en) * | 1985-11-08 | 1987-05-21 | Yutani Juko Kk | Warming up for hydraulic pilot circuit |
| JPH02145306U (en) * | 1989-05-11 | 1990-12-10 | ||
| JPH02145305U (en) * | 1989-05-11 | 1990-12-10 |
-
1981
- 1981-07-31 JP JP56119214A patent/JPS5821006A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3272788B1 (en) | 2016-07-22 | 2020-07-08 | Ricoh Company, Ltd. | Resin powder for solid freeform fabrication, device for solid freeform fabrication object, and method of manufacturing solid freeform fabrication object |
| WO2020213586A1 (en) | 2019-04-16 | 2020-10-22 | コニカミノルタ株式会社 | Resin powder for three-dimensional molding, three-dimensional molded article, and method for producing three-dimensional molded article |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5821006A (en) | 1983-02-07 |
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