Vacuum pressure gelling mold, system and casting method for casting casting material onto component

Abstract

The invention relates to a vacuum pressure gelling tool (10) for pouring a pouring compound (26) onto a component (14), comprising: a casting mold (12) into which the component (14) can be placed; a nozzle receptacle (30) with which a pouring nozzle (28) can be docked, whereby a pouring material (26) can be injected into the vacuum pressure gelling tool (10) via the docked pouring nozzle (28); a connecting line (32), which fluidically connects the nozzle receptacle (30) to the casting mould (12), whereby the casting compound (26) can be conducted from the nozzle receptacle (30) to the casting mould (12) and vacuum-cast onto the component (14); and a conveying device (34), by means of which the casting compound (26) in the connecting line (32) can be conveyed.

Description

TECHNICAL FIELD

[0001] The invention relates to a vacuum pressure gelation mold for casting a casting material onto a component, a system for carrying out vacuum pressure gelation and a method for casting a casting material onto a component by means of a system for carrying out vacuum pressure gelation. BACKGROUND

[0002] WO 2020 / 043381 A1 discloses a mold for injection encapsulation or potting of a rotor. Injection encapsulation, casting encapsulation or potting is carried out here by means of a casting method, in particular by means of vacuum pressure gelation. Two-component thermoset plastics, in particular resin and curing agent, are separated, pretreated under vacuum and the material mixture is fed from below into a placement chamber, gelled and cured in the mold under pressure.

[0003] Furthermore, a method for determining the required metering volume for injection encapsulation, potting or casting encapsulation of a component is disclosed from DE 102019128499 A1. In order to fix a rotor on an electric current excited synchronous machine, the rotor is placed into a mold or a mold cavity and injection encapsulated or casting encapsulated with a potting compound. The rotor is fixed here, in particular by means of vacuum pressure gelation. SUMMARY

[0004] It is the task of the invention to provide a solution which enables particularly time-saving vacuum pressure gelation of a plurality of components.

[0005] The task is solved by the technical solution of the independent claims. Further possible design options of the invention are disclosed in the dependent claims, the description and the drawings. The features, advantages and possible design options set out in the description for one of the technical solutions of the independent claims can be considered at least analogously as features, advantages and possible design options of the respective technical solution of the other independent claims and of any possible combination of the technical solutions of the independent claims, if necessary in combination with one or more dependent claims.

[0006] The invention relates to a vacuum pressure gelation mold for casting a casting material onto a component. In particular, a resin as a casting material is cast onto a component by means of the vacuum pressure gelation mold or a component is potted by means of the casting material. The vacuum pressure gelation mold comprises a mold into which the component can be placed. Furthermore, the vacuum pressure gelation mold comprises a nozzle receptacle, to which a casting nozzle can be docked, whereby the casting material can be injected into the vacuum pressure gelation mold by means of the docked casting nozzle. In other words, the casting material is provided by the casting nozzle and injected into the vacuum pressure gelation mold via the nozzle receptacle. After the casting material has been injected into the vacuum pressure gelation mold via the nozzle receptacle by means of the casting nozzle, the casting nozzle can be separated from the nozzle receptacle and removed. The casting nozzle can thus be used to fill another vacuum pressure gelation mold with casting material. Thereby, a particularly large number of vacuum pressure gelation molds can be filled with casting material by means of one casting nozzle within a particularly short time interval.

[0007] The vacuum pressure gelation mold further comprises a connecting line, which fluidically connects the nozzle receptacle with the mold, whereby the casting material can be guided from the nozzle receptacle to the mold and whereby the casting material is vacuum pressure cast onto the component. In order to avoid that the casting material, when age-hardening, produces undesirable shrinkage cavities or pores on the component due to volume shrinkage, the vacuum pressure gelation mold comprises a delivery device, by means of which the casting material in the connecting line can be delivered. This means that the delivery device is provided for replenishing the casting material in the connecting line and thus pushing it into the mold. By means of the delivery device it can be ensured that the casting material in the mold is always under pressure during age-hardening in such a way that the casting material provided in the connecting line is pushed in the direction of the mold and thus delivered by means of the delivery device.

[0008] When vacuum pressure gelation is carried out, the casting material, in particular the casting resin, is subjected to a chemically induced shrinkage when it is age-hardened, which can lead to shrinkage cavities and cracks. It is therefore provided that the casting material is age-hardened under pressure. Here, the casting material is continuously pressed against the mold during the age-hardening in order to compensate for the shrinkage. As a result, particularly short age-hardening times can be achieved. When vacuum pressure gelation is carried out, the casting material is pressed against the mold under pressure and the pressure is maintained during the age-hardening of the casting material in the mold. The mold is therefore designed to be particularly pressure-resistant. When vacuum pressure gelation is carried out, a vacuum is applied to the mold in order to cast the casting material bubble-free onto the component. Since an absolute vacuum is technically difficult to achieve, a residual pressure of a few millibars can be present in the mold during casting. If air bubbles are formed in the mold when the casting material is cast, these are almost completely compressed when the vacuum is broken. The air bubbles that can occur are compressed to a very small volume when the intake pressure is brought to atmospheric pressure. As a result, the casting material can be cast particularly bubble-free onto the component in the context of vacuum pressure gelation, and particularly short age-hardening times can be achieved here.

[0009] The pressure of the casting material in the mold during the age-hardening of the casting material is usually maintained by means of a casting nozzle by means of which the casting material is additionally pressed. But the casting nozzle for this has to remain on the vacuum pressure gelation mold and cannot be used to fill another vacuum pressure gelation mold during the age-hardening. The described vacuum pressure gelation mold allows the casting material in the mold to be reliably age-hardened under pressurized conditions, without the casting nozzle having to additionally press the casting material into the vacuum pressure gelation mold during the entire age-hardening. Instead, after the casting material has been injected into the vacuum pressure gelation mold, the casting nozzle can be separated from the vacuum pressure gelation mold and used to fill another vacuum pressure gelation mold with casting material. The described vacuum pressure gelation mold allows a plurality of vacuum pressure gelation molds to be particularly time-efficiently supplied with casting material by means of a single casting nozzle.

[0010] In one possible refinement of the application, it is provided that the delivery device comprises a push rod which is guided in the connecting line and by means of which the casting material arranged in the connecting line can be delivered to the mold. The push rod can in particular be moved in translation in the connecting line in the longitudinal extension of the connecting line, whereby the casting material in the connecting line can be pressed in the direction of the mold by means of the push rod. The outer diameter of the push rod corresponds to the inner diameter of the connecting line, whereby the push rod at least substantially completely covers the cross section of the connecting line. It can thus be ensured that the casting material arranged in the connecting line is reliably pressed in the direction of the mold by means of the push rod. It can thus be well avoided that the casting material flows past the push rod when the casting material is attempted to be pressed in the direction of the mold by means of the push rod.

[0011] In a further possible design of the application it is provided that the vacuum pressure gelation mold comprises a pressure sensor, which is arranged in the casting mold. By means of the pressure sensor it is possible to determine the pressure of the casting material which is cast into the casting mold. Furthermore, the delivery device is provided for delivering the casting material in the connecting line depending on the determined pressure. Thus, during the vacuum pressure gelation it is determined by means of the pressure sensor what pressure the casting material has in the casting mold. Depending on the pressure determined by the pressure sensor, the delivery device delivers the casting material in the connecting line in order to adjust or maintain a predetermined pressure of the casting material in the casting mold. By the interaction of the pressure sensor and the delivery device it is possible to particularly reliably ensure that the pressure of the casting material in the casting mold is maintained during the aging of the casting material.

[0012] In a further possible design of the application it is provided that the vacuum pressure gelation mold comprises a heating device by means of which the casting material arranged in the connecting line can be heated. The heating device can prevent, for example, that the casting material in the connecting line cools down. The heating device is provided for heating the casting material, whereby the flowability of the casting material can be maintained. Thereby it is possible to age the casting material in the connecting line and the risk of a clogging of the connecting line is kept particularly small.

[0013] In a further possible design of the application it is provided that the casting mold is provided for accommodating a rotor of a motor vehicle traction machine, whereby the vacuum pressure gelation mold can at least partially pot the rotor with potting compound as casting material. The potting compound can be used, on the one hand, for realizing an electrical insulation of the respective region of the rotor and, on the other hand, for ensuring a particularly good heat transfer in defined regions of the rotor. The particularly good heat transfer based on the potting compound makes it possible for the rotor to be cooled particularly well during operation and thus for the traction machine having the rotor to be operated particularly efficiently. The vacuum pressure gelation mold is thus provided for potting the rotor with potting compound as casting material.

[0014] The application also relates to a system for carrying out vacuum pressure gelation, having a vacuum pressure gelation mold as already described in connection with the vacuum pressure gelation mold according to the application. Furthermore, the system comprises a pouring nozzle, which is provided for reversibly connecting to the vacuum pressure gelation mold. Furthermore, the pouring nozzle is provided for injecting a pouring material into the vacuum pressure gelation mold in the state of connection to the vacuum pressure gelation mold. After the injection of the pouring material into the vacuum pressure gelation mold and while the pouring material is still in the mold of the vacuum pressure gelation mold during the aging hardening, the pouring nozzle can be detached from the nozzle accommodation of the vacuum pressure gelation mold, whereby another vacuum pressure gelation mold can be filled with the pouring material by means of the pouring nozzle. A supplementary pushing of the pouring material into the mold during the aging hardening of the pouring material in the vacuum pressure gelation mold can be achieved by means of a delivery device, by means of which the pouring material provided in the connecting line is pushed into the mold.

[0015] The application also relates to a method for pouring a pouring material onto a component by means of a system as already described in connection with the system for carrying out vacuum pressure gelation according to the application. In particular in the context of the method, a rotor is encapsulated as a pouring material. In the method, the component is provided in the mold of the vacuum pressure gelation mold. Furthermore, the pouring nozzle is coupled to the vacuum pressure gelation mold by means of the nozzle accommodation. Then, the pouring material is injected into the vacuum pressure gelation mold by means of the pouring nozzle. In the method, the pouring material provided in the connecting line is delivered to the mold by means of a delivery device. By delivering the pouring material in the connecting line to the mold by means of the delivery device, a volume shrinkage of the pouring material due to the aging hardening of the pouring material can be compensated in the mold. Thus, in the method, the pouring material is poured onto the component, in particular the rotor, by means of vacuum pressure gelation.

[0016] In a possible extension of the application, it is provided that the pouring material in the connecting line is delivered by means of the delivery device after the pouring nozzle is detached from the nozzle accommodation. In other words, only when the pouring nozzle is detached from the nozzle accommodation, the pouring material provided in the connecting line is delivered to the mold by means of the delivery device. As long as the pouring nozzle is coupled to the nozzle accommodation, the pouring material is pushed into the mold from the pouring nozzle by means of a supplementary pushing of the pouring material through the connecting line. In other words, as long as the pouring nozzle is coupled to the nozzle accommodation, the delivery of the pouring material in the connecting line is inhibited. As soon as the pouring nozzle is removed from the nozzle accommodation, the pouring material provided in the connecting line is supplementary pushed by means of the delivery device in order to maintain the pressure in the mold, whereby a shrinkage of the pouring material during the aging hardening can be compensated.

[0017] In another possible design of the application it is provided that the pressure in the mold is detected by means of a pressure sensor and the delivery rate of the casting compound in the connecting line is adjusted by means of the delivery device in such a way that the pressure of the non-age-hardened casting compound in the mold remains constant until the casting compound is completely age-hardened. In other words, the delivery of the casting compound in the connecting line takes place in dependence on the pressure of the casting compound in the mold as detected by the pressure sensor. The casting compound in the connecting line is delivered by means of the delivery device in such a way that a predetermined pressure of the casting compound in the mold can be maintained. Thereby, on the one hand a particularly rapid age-hardening of the casting compound in the mold can be achieved and on the other hand a reliable compensation of the shrinkage of the casting compound upon shaping can be achieved.

[0018] Further features of the present application can be gathered from the claims, the drawings and the figures of the description. The features and feature combinations mentioned above in the description and below in the figures of the drawings alone or in any combination are possible solutions of the present application, without departing from the scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings show:

[0020] Figure 1 a schematic perspective view of a vacuum pressure gelation mold for casting encapsulating material onto a rotor of a motor vehicle traction machine; and

[0021] Figure 2 a partially schematic sectional view of a system comprising a vacuum pressure gelation mold, the system additionally comprising a casting nozzle.

[0022] In the drawings, identical and functionally identical elements are provided with the same reference signs. DETAILED DESCRIPTION

[0023] The vacuum pressure gelation mold 10 is shown in Figure 1 The vacuum pressure gelation mold 10 comprises a mold 12 into which a component 14 can be placed. In the present case, a rotor is placed as the component 14 into the mold 12. The mold 12 is radially outwardly surrounded in the present case by a bell 16, axially upwardly closed by an upper core-drawing device 18 and radially downwardly closed by a lower core-drawing device 20. The lower core-drawing device 20 comprises a lower support disk 22, on which the component 14, in the present case the rotor, is placed when the component 14 is accommodated in the mold 12. The vacuum pressure gelation mold 10 is shown in Figure 2 partially sectioned in

[0024] In order to thermally insulate the bell jar 16, a thermal insulation jacket 24 can be installed on the radially outer circumference of the bell jar 16, by means of which the bell jar 16 can be thermally insulated. The bell jar 16 can be heated in the present case. The mold 12 is configured in the present case at least substantially cylindrically, whereby the rotor as component 14 can be arranged in the mold 12 and can be encapsulated with the casting material 26.

[0025] Figure 2 A system for performing vacuum pressure gelation is shown. The system for performing vacuum pressure gelation comprises on the one hand a vacuum pressure gelation mold 10 and on the other hand a casting nozzle 28. The casting nozzle 28 is provided for providing a casting material 26 for vacuum pressure gelation. The vacuum pressure gelation mold 10 has a nozzle accommodation 30, into which the casting nozzle 28 can be inserted. In the state in which the casting nozzle 28 is inserted into the nozzle accommodation 30, the casting material 26 can be injected into the vacuum pressure gelation mold 10 by means of the casting nozzle 28.

[0026] In the present case, the casting material 26 is injected into a connecting line 32 of the vacuum pressure gelation mold 10 by means of the casting nozzle 28. The connecting line 32 is in fluid connection with the mold 12. This means that the casting material 26 injected by the casting nozzle 28 into the connecting line 32 is guided through the connecting line 32 to the mold 12, in which the component 14, in the present case a rotor, in particular a rotor winding head of the rotor, is encapsulated with the casting material 26. In order to perform vacuum pressure gelation, a particularly low pressure, in particular a vacuum, can be set in the mold 12. The casting material 26 is pressed under pressure into the vacuumed mold 12. Due to the vacuum set in the mold 12, it is possible to particularly effectively avoid the casting material from developing air bubbles, for example at corresponding undercuts. In order to compensate for the volume shrinkage of the casting material 26 that occurs when the casting material 26 pressure gels and age hardens, it is provided that, during the age hardening of the casting material 26 in the mold 12, further casting material 26 is supplied to the mold 12 when performing vacuum pressure gelation.

[0027] In the current provision, once a certain amount of the casting material 26 for vacuum pressure gelation has been injected into the vacuum pressure gelation mold 10 by means of the casting nozzle 28, the casting nozzle 28 is detached from the nozzle receptacle 30. The casting nozzle 28 can thus be used to fill another vacuum pressure gelation mold 10. In order to still ensure a replenished delivery of the casting material 26 into the mold 12 during the aging hardening, even if the casting nozzle 28 has been removed from the vacuum pressure gelation mold 10, the vacuum pressure gelation mold 10 comprises a delivery device 34. The current delivery device 34 comprises a push rod 36. The push rod 36 is movable in the connecting line 32, in particular is translatory movable along the longitudinal extension of the connecting line 32. By the movement of the push rod 36 in the connecting line 32, the casting material 26 arranged in the connecting line 32 is pushed by the push rod 36 in the direction of the mold 12. Thereby, on the one hand the casting pressure in the mold 12 can be maintained and on the other hand a volume shrinkage of the casting material 26 upon aging hardening can be compensated in the mold 12.

[0028] In the mold 12, a pressure sensor 38 is currently provided, which is schematically represented in a box. The pressure sensor 38 is provided for determining the pressure of the casting material 26 in the mold 12. The delivery device 34 in turn is provided for adjusting the delivery speed and / or the delivery force of the delivery of the casting material 26 in the connecting line 32 depending on the pressure of the casting material 26 in the mold 12 as measured by means of the pressure sensor 38. In particular, the delivery speed of the casting material 26 in the connecting line 32 is adjusted by means of the delivery device 34 such that the pressure of the casting material 26 in the mold 12 which is not yet aged hardens remains constant until the casting material 26 is completely aged hardened.

[0029] In order to avoid an aging hardening of the casting material 26 in the connecting line 32, a heating device 40 can be provided in the vacuum pressure gelation mold 10. By means of the heating device 40, the casting material 26 arranged in the connecting line 32 can be heated. Alternatively or additionally, by means of the heating device 40, a sprue can be shaped. The sprue is a part which does not belong to the shaped piece when the casting material 26 is cast. The sprue is produced by the casting material 26 which solidifies in the connecting line 32.

[0030] The rotor which is put into the mold 12 as the component 14 can have six holes each on its mutually opposite end faces. During the vacuum pressure gelation, the six upper holes in the mold 12 are all sealed. The rotor has four of the six lower holes in the vacuum pressure gelation mold 10 sealed, the pressure sensor 38 is located in one of the holes and the casting material 26 is injected into the rotor via the last hole.

[0031] After the filling process, the injection nozzle 28 is undocked from the vacuum pressure gelation mold 10. Thereby, the pressure monitoring by means of the injection nozzle 28 cannot be used to adjust the pressure maintenance. During the filling process, and thus during the docking of the injection nozzle 28 with the vacuum pressure gelation mold 10, the pressure monitoring by means of the pressure sensor 38 takes place, which can also be referred to as mold interior pressure sensor. The filling phase by means of the injection nozzle 28 takes place in a pressure-controlled manner. After the undocking of the injection nozzle 28 from the vacuum pressure gelation mold 10, the push rod 36 supplements the remaining material in the connecting line 32, which can also be referred to as injection rod, in a force stroke-controlled manner and thus compensates for the material shrinkage in the gelation phase. For this purpose, the sensor data of the pressure sensor 38 can be averaged and extrapolated. After the removal of the injection nozzle 28 from the vacuum pressure gelation mold 10, the push rod control is switched on and thus the pressure maintenance is adjusted in a force-controlled manner by means of the push rod 36.

[0032] In summary, the present application shows how an optimization of the control process for vacuum pressure gelation can be achieved.

[0033] List of reference signs

[0034] 10 vacuum pressure gelation mold

[0035] 12 mold

[0036] 14 component

[0037] 16 bell

[0038] 18 upper core pulling device

[0039] 20 lower core pulling device

[0040] 22 support plate

[0041] 24 thermal insulation jacket

[0042] 26 injection material

[0043] 28 injection nozzle

[0044] 30 nozzle receptacle

[0045] 32 connecting line

[0046] 34 conveying device

[0047] 36 push rod

[0048] 38 pressure sensor

[0049] 40 heating device

Claims

1. A vacuum pressure gelling mold (10) for casting material (26) onto a component (14), the vacuum pressure gelling mold comprising: The mold (12) is into which the component (14) can be placed; The nozzle receiving part (30) is able to dock with the pouring nozzle (28), thereby allowing the pouring material (26) to be injected into the vacuum pressure gelling mold (10) through the docked pouring nozzle (28); A connecting pipe (32) fluidly connects the nozzle housing (30) to the mold (12), thereby enabling the casting material (26) to be guided from the nozzle housing (30) to the mold (12) and the casting material (26) to be vacuum die-cast onto the component (14); and The conveying device (34) is used to convey the casting material (26) in the connecting pipe (32).

2. The vacuum pressure gelling mold (10) according to claim 1, characterized in that, The conveying device (34) includes a push rod (36) guided in the connecting pipe (32), by means of which the casting material (26) disposed in the connecting pipe (32) can be conveyed to the mold (12).

3. The vacuum pressure gelling mold (10) according to claim 1 or 2, characterized in that, A pressure sensor (38) is provided in the mold (12) to detect the pressure of the casting material (26) poured into the mold (12), and the conveying device (34) is provided to convey the casting material (26) in the connecting pipe (32) according to the determined pressure.

4. The vacuum pressure gelling mold (10) according to any one of the preceding claims, characterized in that, A heating device (40) is provided, by means of which the casting material (26) disposed in the connecting pipe (32) can be heated.

5. The vacuum pressure gelling mold (10) according to any one of the preceding claims, characterized in that, The mold (12) is provided to accommodate the rotor of the traction machine for motor vehicles, thereby enabling the rotor (12) to be at least partially filled with potting compound as casting material (26) by means of a vacuum pressure gelling mold (10).

6. A system for performing vacuum pressure gelling, the system having a vacuum pressure gelling mold (10) according to any one of the preceding claims and having a pouring nozzle (28) configured to reversibly connect with the vacuum pressure gelling mold (10) and, in the state of connection with the vacuum pressure gelling mold (10), pouring material (26) into the vacuum pressure gelling mold (10).

7. A method for casting casting material (26) onto a component (14) by means of the system according to claim 6, wherein, The component (14) is placed in the mold (12), and the pouring nozzle (28) is coupled to the vacuum pressure gelling mold (10) through the nozzle receiving part (30). The pouring material (26) is injected into the vacuum pressure gelling mold (10) by means of the pouring nozzle (28), and the pouring material (26) placed in the connecting pipe (32) is transported to the mold (12) by means of the conveying device (34). Thus, the volume shrinkage of the pouring material (26) caused by the age hardening of the pouring material (26) can be compensated in the mold (12).

8. The method according to claim 7, characterized in that, After the pouring nozzle (28) is disconnected from the nozzle housing (30), the pouring material (26) in the connecting pipe (32) is conveyed by means of the conveying device (34).

9. The method according to claim 7 or 8, characterized in that, The pressure in the mold (12) is detected by means of a pressure sensor (38), and the conveying speed of the casting material (26) in the connecting pipe (32) is adjusted by means of a conveying device (34) so ​​that the pressure of the unaged casting material (26) in the mold (12) remains constant until the casting material (26) is fully aged and hardened.

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