FR2727646A1 - HEATED BODY FOR A NOZZLE SUPPORT - Google Patents

Abstract

Disclosed is a heating body for an injection nozzle holder of a plastic injection molding mold, comprising a heating wire which is disposed surrounding the nozzle holder, a thermoelectric sensor which is for measuring the temperature on the nozzle holder and a locking member which is intended to hold the heating wire on the nozzle holder. This heating body is characterized by the fact that the heating wire (9) is arranged in a heating wire support (3) in the form of a hollow cylinder, and by the fact that at least one recess (13) is provided in the surface side of the heating wire support (3) to receive the thermoelectric sensor. Application to the molding of plastic material by injection.

Description

DESCRIPTION

D E S C R I P T I 0 N

  The subject of the invention is a heating body des-

  tine & injection mold support of a molding mold

  plastic injection material, comprising a heating wire

  which is arranged by surrounding the nozzle support, a cap-

  thermoelectric sensor which is intended to measure the temperature on the nozzle support and a locking member which is

  for holding the heating wire on the nozzle support.

  To produce and maintain a constant temperature

  on the injection nozzles of the injection molding molds

  It is known to place a heating body on the nozzle support. This heating body thus surrounds the nozzle support,

  essentially, on a particular part or on the totality of

  its length. The production of heat in the body

  heating takes place by means of heating coils which are

  placed in the heating body, preferably in the form of

  contention. A known heating body is constituted for example by

  a cylinder-shaped sheet in which the coils

  fantes are put in place by extending in the shape of a helix.

  This sheet metal wall can be contracted by means of a screw, in order to tighten the heating turns on the nozzle support and to allow a fixation thereon. To measure the temperature on this nozzle support, a groove that extends parallel to the axis of symmetry is milled into its surface.

  lateral. It is in this groove that we push a cap-

  thermoelectric rod-shaped head which is located parallel

  the axis of symmetry of the nozzle and which is held by the turns of the heating, the latter covering the wall of the

nozzle support.

  To be able to replace a defective thermoelectric sensor, it is necessary to undo the fixation of the body

  heat and remove it from the nozzle holder. The replacement

  Placement of the thermoelectric sensor takes a lot of time and, during the manufacture of the nozzle support, it is necessary to machine in its surface the groove which is intended for the thermoelectric sensor. This represents a machining operation

  extra during its manufacture.

  The purpose of the present invention is then to

  to perfect a heating body of the kind mentioned above

  such that the replacement of a defective thermoelectric sensor can be achieved in a simple and

cost-effective.

  This object is achieved according to the invention by virtue of a heating body which is characterized in that the heating wire is arranged in a heating wire support in

  hollow cylinder shape, and in that at least one hollow

  is provided in the lateral surface of the wire support

  heater to receive the thermoelectric sensor.

  The integration of the heating element location with the thermoelectric sensor has the effect that no need is made for the nozzle support to receive the thermoelectric sensor. In addition, the heating body can be placed on the nozzle support in any position. This allows to move away from the heating body the connection wires that lead to the thermoelectric sensor and to place them in the position which is the

  more appropriate. The heater and the sensor can be replaced

  placed on the injection machine without disassembly of the injection molding mold. The fixing of the heating body and the tightening of the thermoelectric sensor on the nozzle support take place by means of a threaded rod which is arranged on the heating body. It is also easy to mount two thermoelectric sensors on a heating body, in order to

  be able to measure the temperature at both ends. The cap-

  The thermoelectric sensor is housed in a robust disk-shaped head, and it can be inserted in a simple manner into the heating body which is pressed onto the support.

  nozzle, or removed from it, respectively. The manufacture

  of the heating body and the opening forming the housing which is intended for the thermoelectric sensor is very simple

and a very advantageous cost.

  The invention is explained in a more

  detailed with the help of an example of

  sented. The figures show: FIG. 1 a perspective view of a heating body, FIG. 2 a perspective view of a thermoelectric sensor provided with a head, FIG. 3 a longitudinal section of a nozzle support including the nozzle FIG. 4 is a perspective view of another heating body, FIG. 5 is a perspective view of a thermoelectric sensor that can be screwed in. FIG. 6 is a longitudinal section of FIG. other heating body,

  Figure 7 is a cross-section of the heated body

Figure 6, and:

  Figure 8 is a perspective view of another

  realization of a thermoelectric sensor that can be

screwed.

  The heating body 1 according to a first embodiment represented in FIG.

  heating wire 3 in the form of a hollow cylinder, both of which

  front faces 5 and 7 are arranged extending perpendicularly

  Cultivated to the axis of symmetry of revolution A. A heating spiral or a heating wire 9 is embedded in the form of a helix inside the wall of the heating wire support 3. For clarity, only two turns of the wire heating 9 were

  shown in dashed lines in Figure 1. Of course,

  of, heating done in another way could be

  also used in place of a heating wire 9. This is pre-

  in the area of the frontal surface 5 or the surface

  front face 7 that the two connecting son 11 which are intended for the heating wire 9 are brought to the outside of the side surface of the support 3 of the heating wire. This support 3

  is made of brass or other good conductive material

  tor. In the front surface 5 is formed a recess 13 which preferably extends parallel to the axis A and which is formed in the form of a semicircle on its bottom 15. In cross section, the recess 13 has the shape of a T-groove, which means that its width is smaller in the

  direction of the external lateral surface than on the

  the support 3 of the heating wire.

  By its conformation, the recess 13 is intended to receive a thermoelectric sensor 17 which has a head 19 in the form of a disc. A narrowed portion 23 is mounted on

  the head 19, and it constitutes the anchoring of the cables 21 of the cap.

  tor. The head 19 and the narrowed portion 23 have the shape of a T in longitudinal section, and they are adjusted to the

  cross section of the recess 13 (Figure 2).

  A threaded bore 25 for receiving a threaded rod 27 is provided in the side surface of the wire support 3 of the heating wire at a location which is diametrically opposite

at the recess 13.

  The recess 13 and the threaded hole 25 can be

  also arranged in the region of the frontal surface 7.

  It is further possible to provide recesses 13 and

  threaded holes 25 in both front surfaces 5 and 7.

  In FIG. 3, the heating body 1 is

  when the nozzle support 29 surrounds the major part of the nozzle 31. The thermoelectric sensor 17 is depressed into the upper recess 13, and is tight. against the surface

  nozzle support 29 by the threaded rod 27 which is

  opposite. This ensures a perfect contact with the lateral surface of the nozzle support 29. The threaded rod 27 serves at the same time to maintain the heating body 1 on the

nozzle support 29.

  Unlike the representation of Figure 1,

  the connection wires 11 of the heating wire 9 leave the support

  port 3 of this heating wire in the vicinity of the recess 13.

  This allows common guidance of the connection wires 11 and

  targets 21 which are intended for the thermoelectric sensor 17.

  In the second embodiment according to FIGS. 4 and 5, the heating element 101 again has the shape of a hollow cylinder, and its front surfaces 105 and 107 are located perpendicular to the axis of symmetry of

  revolution A. The heating coils 109 are again dis-

  placed inside the wall of the support 103 of the heating wire

  ghost, and they are indicated in broken lines. Both

  connection wires 111 which are intended for heating turns

  109 come out of the lateral surface of the support 103 of the heating wire in the region of the frontal surface 105 or the

frontal surface 107.

  A radially extending threaded bore 113 is formed in the support 103 of the heating wire, preferably in the vicinity of the exit of the connection wires 111. Another threaded bore may be provided at another location, and preferably in the vicinity of the lower frontal surface

  107. The threaded bore 113 serves to receive a heat sensor

  117 which is carried by a threaded rod 127. The

  thermoelectric sensor 117 has the shape of a T in sec-

  longitudinally, its upper flange forming a disk-shaped head 119 whose diameter is greater than that of the bore 128 which is formed in the threaded rod 127. The cylindrical narrowed portion 123 of the thermoelectric sensor 117 is located inside the bore 128 through which the connection cables 121 of the thermoelectric sensor 117

are brought outside.

  In a conformation variant of the invention, the thermoelectric sensor 117 can be completely embedded

  in the bore 128 of the threaded rod 127, its frontier surface

  tale coming from the plane of the front end of the

threaded rod (Figure 8).

  In operation, the heater wire support 103 is depressed on a nozzle support 129, and by

  example on the one shown in Figure 3. The

  Thermoelectric actuator 117 is screwed into the threaded hole 113 accompanying the threaded rod 127. When the latter is fully screwed, the head 119 of the thermoelectric sensor

  117 is jammed on the surface of the nozzle support 129.

  A perfect thermal connection is here produced between the

  nozzle port 129 and the thermoelectric sensor 117, on the one hand, and, on the other hand, the support 103 of the heating wire is

  held on the nozzle support 129.

  In the threaded bore 113 which is located at the other end of the support 103 of the heating wire, it is possible to introduce a second thermoelectric sensor 117, or it can be

  simply screw another fixing screw.

  When the thermoelectric sensor 117 is defective

  killer, it can be replaced in the simplest way in

unscrewing the threaded rod 127.

  In the third embodiment according to the

  FIGS. 6 and 7, the heating turns 209 extend in

  propeller inside a heater wire holder 203 which is made from a curved cylinder tile. The

  heating turns 209 may be welded to the wall

  the support of the heating wire, or they can bear on this wall adhering only by friction. The connection wires 211 of the heating turns 209 come out again from the support 203 of the heating wire in the region of a frontal surface 205 or 207. This is also in the region

  of a frontal surface 205 or 207 that is formed in the sur-

  lateral face of the support 203 of the wire heating a bore 212 in which is inserted a threaded sleeve 213 which is pressed from the inside. We can introduce in this threaded sleeve

  a thermoelectric sensor similar to that which is

  shown in Figure 5 and which has been described about this

  this. The thermoelectric sensor is not represented on the

Figure 6 for clarity.

  The mode of operation and the manipulation of the third exemplary embodiment according to FIGS. 6 and 7

  are identical to those of the second embodiment.

Claims (10)

- CLAIMS -   1. Heating body for a nozzle holder   jection of a plastic molding mold by injecting   including a heating wire which is arranged in a   the nozzle holder, a thermoelectric sensor which is intended to measure the temperature on the nozzle support and a   blocking member which is intended to hold the heating wire   on the nozzle support, characterized by the fact that the heating wire (9, 109, 209) is arranged in a heating wire support (3, 103, 203) in the form of a hollow cylinder, and by the fact that at least one recess (13, 113, 123) is provided in the side surface of the support (3, 103, 203) of the heating wire for receiving the thermoelectric sensor (17, 117).   2. Heating body according to claim 1, characterized   characterized in that a slot-like recess (13) is provided on at least one end surface (5) of the heating wire support (3) for driving and maintaining the thermoelectric sensor (17).   Heating body according to claim 2, characterized   due to the fact that the recess (13) is in the form of a groove whose cross section is shaped   of T, and that it extends parallel to the axis of symmetry (A).   4. Heating body according to claim 3, characterized   rised by the fact that the recess (13) is made in the form of semicircle on its bottom.   Heating body according to one of claims 2 to   4, characterized in that the thermoelectric sensor (17) comprises a disc-shaped head (19) and a part   narrowed (23) which can be driven axially into the recess (13).   6. Heating body according to one of the claims   1 to 5, characterized in that a threaded rod (27)   is introduced into a threaded bore (25) while being diametrically   opposite to the recess (13).   7. Heating body according to claim 1, characterized   rised by the fact that the recess in the lateral surface   the support (103, 203) of the heating wire is in the form of a threaded bore (113) or a non-threaded bore (212) which receives a threaded sleeve (213), and in that the thermoelectric sensor (117) is held in a threaded rod (127) which can be screwed radially   with it in the recess (113, 213).   Heating body according to claim 7, characterized   rised by the fact that the threaded rod (127) has a perforation   ge (128) which extends axially and in which the sensor   thermoelectric (117) can be depressed.   Heating body according to claim 8, characterized   the fact that the thermoelectric sensor (117) pre-   a disc-shaped head (119) which is located at the front end of the threaded rod (127) and outside piercing (128).   10. Heating body according to one of the claims   7 to 9, characterized by the fact that two heat sensors   electrodes (117) are introduced into the carrier (103, 203) of the heating wire.