Aluminum piston pouring gate and casting mold structure and casting method of aluminum piston pouring gate and casting mold structure

Abstract

The invention discloses an aluminum piston pouring gate which comprises a straight pouring gate, a transverse pouring gate communicated with the straight pouring gate, a hidden pouring gate and an inner pouring gate communicated with the transverse pouring gate, the inner pouring gate is of a variable cross-section structure, and the hidden pouring gate is arranged below the transverse pouring gate and communicated with the hidden pouring gate; the invention further provides a piston casting mold for forming the aluminum piston pouring gate and a casting method of the piston casting mold. According to the invention, the cast piston blank does not need to feed the ingate through a cross gate, the cross gate does not need to be coated with a thermal insulation coating, and the loose defect and the inclusion defect are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of piston casting, and particularly to an aluminum piston runner and a casting mold structure and a casting method thereof. Background Art

[0002] An aluminum alloy piston is formed into a piston blank through a piston metal casting mold, and the piston blank is processed subsequently to obtain a finished piston. The piston is in a harsh environment of high temperature, high pressure and high speed in the engine for a long time. Therefore, the piston must have very good mechanical properties, and there should be no defects such as porosity and inclusion in the piston matrix. The piston blank is formed by a casting mold, and the molten aluminum enters the mold cavity through the runner and solidifies to obtain the piston blank. The existing piston blank structure mainly includes a sprue, a runner and an ingate. The molten aluminum flows from the sprue into the runner, then from the runner into the ingate, and then into the mold cavity to form the piston body. The ingate is connected from the lower skirt of the piston to the upper head. Since the piston has a structure with a thin wall at the lower skirt and a thick wall at the upper head, this product structure is prone to porosity defects at the ingate. To avoid porosity defects at the ingate of the piston blank, it is necessary to apply a heat-insulating coating on the runner to slow down the solidification rate of the molten aluminum in the runner, so that the solidification rate of the molten aluminum in the runner is slower than that of the molten aluminum in the ingate, so that the runner can compensate for the shrinkage of the ingate, thereby improving the porosity defect in the ingate. However, the heat-insulating coating applied on the runner is a loose, porous and brittle coating, and the expansion coefficient of the coating is also inconsistent with that of the metal casting mold, and it is easy to fall off and cause a reduction in the heat-insulating effect. Therefore, the effect of the existing method of applying a heat-insulating coating on the runner is not stable, and it cannot completely ensure the solution of the piston porosity problem. At the same time, after the heat-insulating coating on the runner falls off, the fallen coating particles will enter the mold cavity along with the molten aluminum, and thus remain in the piston body to form piston inclusion defects. Therefore, the existing method of applying a heat-insulating coating on the runner to solve the porosity at the ingate not only cannot completely solve the piston porosity problem, but also causes slag inclusion defects in the piston.

[0003] Regarding the problem of inclusions caused by paint peeling off, the common existing methods mainly include: 1. The runner is designed as a separate heat-insulating material component (such as hardened heat-insulating blocks, heat-insulating ceramic blocks, etc.), and then inlaid on the mold; 2. The runner is designed as a separate hollowed-out metal material component, and then inlaid on the mold; 3. Cutting and hollowing-out grooves are made at the runner of the mold to slow down the heat transfer of the mold; 4. The runner is made larger and thicker to slow down the solidification speed of the molten aluminum, etc. The above methods mainly have the following defects: (1) The thermal expansion coefficient of the heat-insulating material is much smaller than that of the metal mold. The thermal expansion coefficient of the heat-insulating material is small, and the dimensional change at high and low temperatures is not large, but the dimensional change of the mold at high and low temperatures is large. When the hardened heat-insulating block and heat-insulating ceramic block are inlaid on the mold, if the fitting gap is small, when the mold cools down from heat, the volume shrinkage is likely to crush the heat-insulating block and ceramic block and cause peeling and chipping, resulting in piston inclusions again. If the fitting gap is large, when the mold heats up from cold, the volume increases and the gap with the heat-insulating block and ceramic block further increases, resulting in aluminum leakage at the gap and generating flash burrs. The flash burrs are easily carried into the mold cavity by the molten aluminum and cause inclusions. Therefore, the method of using hardened heat-insulating blocks and heat-insulating ceramic blocks is not stable and cannot solve the inclusion problem; (2) The separate hollowed-out metal material component requires a certain thickness, otherwise it will not be strong enough and will deform and crack and cannot be used. The hollowed-out metal material component with a certain thickness will absorb heat from the runner molten aluminum. Therefore, the heat-insulating effect of this method is limited and cannot achieve the effect of applying heat-insulating paint on the runner, and cannot completely solve the porosity problem; (3) Cutting and hollowing-out grooves on the outer side of the runner cannot be close to the runner molten aluminum and require a certain distance, otherwise the runner of the mold will not be strong enough and will deform and crack and cannot be used. Therefore, the heat-insulating effect of this method is limited and cannot achieve the effect of applying heat-insulating paint on the runner, and cannot completely solve the porosity problem; (4) Enlarging and thickening the runner requires enlarging the runner several times to effectively solve the porosity problem. However, after the runner is increased several times, gas entrainment and air entrapment phenomena will occur during the aluminum casting, resulting in new oxidation inclusion phenomena and cannot solve the inclusion problem. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides an aluminum piston runner and casting mold structure and its casting method, which can enable the cast piston blank to not rely on the runner to compensate for shrinkage of the ingate, the runner does not need to be coated with heat-insulating paint, and there will be no porosity defects or inclusion defects.

[0005] The technical solution provided by the present invention is as follows: An aluminum piston runner includes a sprue, a runner communicated with the sprue, a blind runner, and an ingate communicated with the runner. The ingate is a variable cross-section structure, and the blind runner is arranged below the runner and communicated with the blind runner.

[0006] Preferably, the vertical cross-section of the ingate is a T-shaped structure that is narrow at the bottom and wide at the top.

[0007] Preferably, the minimum wall thickness below the ingate is Y, the maximum wall thickness above the ingate is Z, the upward slope of the bottom end of the ingate is N, the downward slope of the top end of the ingate is P, and the height of the narrower cross-section part below the T-shaped structure of the ingate is Q. Y = (0.5 - 0.9)X, Z = (1.5 - 2.5)Y, N = (0.5 - 1.2)M, P = (0.6 - 1.3)M, Q = (1 - 1.5)W, where X is the minimum wall thickness of the skirt below the piston body, M is the draft angle of the skirt below the piston body, and W is the distance from the end face of the skirt below the piston body to the center of the pin hole.

[0008] A piston casting mold includes an inner mold for forming the inner cavity of the piston body, a guide sleeve for forming the lower end face of the piston body, a left outer mold and a right outer mold for forming the outer circle of the piston body, and a mold cover for forming the head of the piston body. The guide sleeve is arranged above the inner mold, the mold cover is arranged above the guide sleeve, the left outer mold and the right outer mold are symmetrically arranged on the left and right sides of the inner mold, and forming cavities for forming the aluminum piston runner as described above are provided in both the left outer mold and the right outer mold.

[0009] Preferably, the left outer mold includes a left sprue block, a left outer mold cover plate, a left runner block, and a left outer mold base. The right outer mold includes a right sprue block, a right outer mold cover plate, a right runner block, and a right outer mold base. The left sprue block and the right sprue block are matched to form the sprue of the piston runner. The left runner block and the right runner block are matched to form the runner and the blind runner of the piston runner. The left outer mold base and the right outer mold base are matched to form the ingate of the piston runner. Temperature measuring probes and heat exchange channels are respectively provided on both the left runner block and the right runner block. The heat exchange channels are communicated with pipeline connectors for connecting high-temperature heating oil for heating the mold or cooling water for cooling the mold.

[0010] Preferably, the heat exchange channel is composed of multiple channels arranged in parallel.

[0011] A method for casting a piston casting mold as described above includes the following operating steps: S1. The casting mold is in the open mold state. Open the corresponding heat exchange channels and heat the left outer mold and the right outer mold respectively. When the corresponding temperature measuring probes detect that the temperatures of both reach the set value, close the mold and close the heat exchange channels. At this time, the casting mold is in the state of waiting for pouring. S2. Pour the aluminum liquid under the closed mold state. After pouring is completed, immediately open the corresponding heat exchange channels for water cooling. When the corresponding temperature measuring probes detect that the cooling temperature reaches the set value, close the cooling water. S3. After the aluminum liquid in the casting mold solidifies, the mold is opened. In the mold-open state, the corresponding heat exchange channels are immediately opened again to heat the left outer mold and the right outer mold respectively, and then the piston blank is taken away to complete a casting cycle and prepare to enter the next casting cycle.

[0012] Preferably, the set temperature for heating the left outer mold and the right outer mold in step S1 is 200 - 250 °C.

[0013] Preferably, the set value of the cooling temperature in step S2 is 50 ± 10 °C.

[0014] Preferably, in steps S1 and S3, heating oil is introduced into the corresponding heat exchange channels to heat the left runner block and the right runner block; in step S2, cooling water is introduced into the corresponding heat exchange channels to cool the left runner block and the right runner block.

[0015] The present invention has the following advantages over the prior art: 1. In the aluminum piston runner of the present invention, a sub-runner is provided below the cross runner. The aluminum liquid is cast from the sprue and first flows into and fills the sub-runner. The sub-runner is located below the cross runner. The purpose of setting the sub-runner is to gather the relatively poor aluminum liquid at the front end of the aluminum liquid flow. This part of the aluminum liquid has a lower temperature and contains oxide inclusions, so that the aluminum liquid flowing into the cross runner subsequently has a higher temperature and less impurity content. At the same time, since the sub-runner is located below the cross runner and is relatively close, the aluminum liquid first fills the sub-runner, and the aluminum liquid in the sub-runner can heat the mold, increasing the temperature of the mold around the cross runner to reduce the temperature loss of the subsequent aluminum liquid flowing through the cross runner, which is beneficial to the casting forming and avoids defects such as cold shut. The inner runner of the aluminum piston runner of the present invention is set as a variable cross-section structure, aiming to increase the temperature gradient for feeding from the upper head to the lower skirt of the piston body, realizing the solidification feeding of the piston body from the upper head to the lower skirt and avoiding the looseness defect of the casting at the inner runner.

[0016] 2. The piston casting mold of the present invention is used in combination with the aluminum piston runner of the present invention and the piston casting method of the present invention, which can effectively solve the looseness problem at the inner runner of the piston blank. Instead of adopting the traditional idea of relying on the cross runner to feed the inner runner, the cross runner is rapidly cooled and solidified, and the feeding is carried out relying on the characteristics that the wall thickness of the upper part of the piston body is larger and the wall thickness of the lower part is smaller to solve the looseness problem at the inner runner. The method of the present invention does not require heat preservation or heat insulation treatment for the cross runner, essentially does not need to apply coatings, and will not have the problem of coating peeling off, and can completely solve the looseness and inclusion defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0018] Figure 1 Structural schematic diagram of the aluminum piston runner in the embodiment of the present invention; Figure 2 is Figure 1 the D-D cross-sectional view in Figure 3 is Figure 1 the E-E cross-sectional view in Figure 4 Structural schematic diagram of the piston casting mold in the embodiment of the present invention; Figure 5 Structural schematic diagram of the left outer mold and the right outer mold in the piston casting mold in the embodiment of the present invention; Figure 6 is Figure 4 the front view of Figure 7 is Figure 6 the N-N cross-sectional view in Figure 8 Partial cross-sectional view of the heat exchange channel of the left / right transverse runner block in the piston casting mold in the embodiment of the present invention.

[0019] Reference numerals: 1, sprue; 2, runner; 3, blind runner; 4, ingate; 5, inner mold; 6, guide sleeve; 7, left outer mold; 71, left sprue block; 72, left outer mold cover plate; 73, left transverse runner block; 74, left outer mold base; 8, right outer mold; 81, right sprue block; 82, right outer mold cover plate; 83, right transverse runner block; 84, right outer mold base; 9, mold cover; 10, temperature measuring probe; 11, heat exchange channel; 12, pipe joint. Detailed implementation manners

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] As Figures 1-8As shown in the figure, an embodiment of the present invention provides an aluminum piston runner, which includes a sprue 1, a runner 2 communicating with the sprue 1, a blind runner 3, and an ingate 4 communicating with the runner 2. The ingate 4 has a variable cross-section structure, and the blind runner 3 is arranged below the runner 2 and communicates with the blind runner 3. Molten aluminum is cast from the sprue 1 and first flows into and fills the blind runner 3. The blind runner 3 is located below the runner 2. The purpose of arranging the blind runner 3 is to gather the poor molten aluminum at the front end of the molten aluminum flow. This part of the molten aluminum has a lower temperature and contains oxide inclusions, so that the molten aluminum flowing into the runner subsequently has a higher temperature and less impurities. At the same time, since the blind runner 3 is located below the runner 2 and is relatively close, the molten aluminum first fills the blind runner 3. The molten aluminum in the blind runner 3 can heat the mold, increasing the temperature of the mold around the runner 2 to reduce the temperature loss when the subsequent molten aluminum flows through the runner 2, which is beneficial to the forming of the casting and avoids defects such as cold shut.

[0022] In this embodiment, the vertical cross-section of the ingate 4 is a T-shaped structure with a narrow lower part and a wide upper part. The ingate 4 is set to have a T-shaped cross-section with a small lower part and a large upper part. The purpose is to increase the temperature gradient for feeding from the upper head to the lower skirt of the piston body, realize the solidification feeding of the piston body from the upper head to the lower skirt, and avoid the porosity defect in the casting on the ingate 4.

[0023] In this embodiment, the minimum wall thickness below the ingate 4 is Y, the maximum wall thickness above the ingate 4 is Z, the upward slope of the lower end of the ingate 4 from bottom to top is N, the downward slope of the upper end of the ingate 4 from top to bottom is P, and the height of the narrower cross-section part below the T-shaped structure of the ingate 4 is Q. Y = (0.5 - 0.9)X. The purpose is to make the cross-sectional width of the ingate smaller than that of the piston body, so that the molten aluminum in the ingate 4 will solidify earlier than the molten aluminum in the piston body, avoiding porosity below the ingate 4.

[0024] Z = (1.5 - 2.5)Y. The purpose is to increase the overall cross-sectional area of the ingate 4, make the molten aluminum flow smoothly, and avoid defects such as jet flow and gas entrapment and slag inclusion caused by too small a cross-section of the ingate when the molten aluminum flows through the ingate 4.

[0025] N = (0.5 - 1.2)M. The purpose is to make the cross-section of the ingate 4 increase from bottom to top, so that the molten aluminum in the ingate can solidify gradually from bottom to top, avoiding porosity in the middle of the ingate 4.

[0026] P = (0.6 - 1.3)M. The purpose is to make the cross-section of the ingate 4 increase from bottom to top, so that the molten aluminum in the ingate 4 can solidify gradually from bottom to top, avoiding porosity in the middle of the ingate 4.

[0027] Q = (1 - 1.5)W. The purpose is that the cross-sectional width of the ingate 4 needs to be determined according to the cross-sectional width of the piston body. The increase in the cross-sectional size above the center line of the piston pin hole is relatively large, and the ingate 4 needs to quickly expand its cross-sectional width. Therefore, the T-shaped cross-section ingate 4 is invented.

[0028] Among them, X is the minimum wall thickness of the skirt below the piston body, M is the draft angle of the skirt below the piston body, and W is the distance from the end face of the skirt below the piston body to the center of the pin hole. The above dimensions are applicable to the application of general aluminum piston structures. When the piston structure is relatively abnormal, appropriate adjustments can be made again.

[0029] The existing piston blanks mainly consist of a piston body and a piston runner. The piston body mainly has structures such as the lower end face of the piston body, the inner cavity of the piston body, the outer circle of the piston body, and the head of the piston body.

[0030] This embodiment provides a piston casting mold, which includes an inner mold 5 for forming the inner cavity of the piston body, a guide sleeve 6 for forming the lower end face of the piston body, a left outer mold 7 and a right outer mold 8 for forming the outer circle of the piston body, and a mold cover 9 for forming the head of the piston body. The guide sleeve 6 is arranged above the inner mold 5, the mold cover 9 is arranged above the guide sleeve 6, the left outer mold 7 and the right outer mold 8 are symmetrically arranged on the left and right sides of the inner mold 5, and forming cavities for forming the aluminum piston runner as described above are provided in both the left outer mold 7 and the right outer mold 8.

[0031] In this embodiment, the left outer mold 7 includes a left sprue block 71, a left outer mold cover plate 72, a left runner block 73, and a left outer mold base 74. The right outer mold 8 includes a right sprue block 81, a right outer mold cover plate 82, a right runner block 83, and a right outer mold base 84. The left sprue block 71 and the right sprue block 81 are matched to form the sprue of the piston runner. The left runner block 73 and the right runner block 83 are matched to form the runner 2 and the subgate 3 of the piston runner. The left outer mold base 74 and the right outer mold base 84 are matched to form the ingate 4 of the piston runner. Temperature measuring probes 10 and heat exchange channels 11 (including a left outer mold temperature measuring probe and a left outer mold heat exchange channel, a right outer mold temperature measuring probe and a right outer mold heat exchange channel) are respectively provided on both the left runner block 73 and the right runner block 83. The temperature measuring probe 10 is used to measure the mold temperature and provide an input for automatically controlling the mold temperature. The heat exchange channel 11 is connected to a pipe joint 12 for connecting high-temperature heating oil for heating the mold or cooling water for cooling the mold. The heat exchange channel 11 is composed of multiple channels arranged in parallel (in this embodiment, the left outer mold and the right outer mold are respectively composed of four channels arranged in parallel). The purpose of setting multiple channels is to strengthen the heating or cooling of the runner blocks (including the left runner block 73 and the right runner block 83).

[0032] A piston casting method using the piston casting mold as described above includes the following operating steps: S1. The casting mold is in the open mold state. Open the corresponding heat exchange channels 11 and heat the left outer mold 7 and the right outer mold 8 respectively. When the corresponding temperature measuring probes 10 detect that the temperatures of both reach the set values, close the mold and close the heat exchange channels 11. At this time, the casting mold is in the state of waiting for pouring. S2. During the closed mold state, perform aluminum liquid casting. After casting is completed, immediately open the corresponding heat exchange channels 11 for water cooling. When the corresponding temperature measuring probes 10 detect that the cooling temperature reaches the set value, close the cooling water. S3. When the aluminum liquid in the casting mold solidifies, open the mold. In the open mold state, immediately open the corresponding heat exchange channels 11 again and heat the left outer mold 7 and the right outer mold 8 respectively. Then take away the piston blank to complete a casting cycle and prepare to enter the next casting cycle.

[0033] As Figure 8 shown, in this embodiment, in the open mold state of step S1, for the two left outer mold heat exchange channels and the two right outer mold heat exchange channels, equipment such as a mold temperature controller can be used to introduce high-temperature heating oil to heat the left runner block and the right runner block. Use the left outer mold temperature measuring probe to detect the temperature of the left runner block, and use the right outer mold temperature measuring probe to detect the temperature of the right runner block. The measured temperature can be input to the computer control system, and the control system can be used to control the opening and closing of the high-temperature heating oil to control the heating temperature of the runner block. Generally, the temperature of the runner block can be set to 200 - 250 °C. When the measured mold temperature is lower than 200 °C, introduce high-temperature heating oil into the two left outer mold heat exchange channels and the two right outer mold heat exchange channels. When the measured mold temperature is higher than 250 °C, stop introducing high-temperature heating oil into the two left outer mold heat exchange channels and the two right outer mold heat exchange channels and stop heating the runner block. It is also possible to set different temperatures for the left runner block and the right runner block according to the structural characteristics of specific different piston products. Due to the setting of multiple heat exchange channels, the runner block can be quickly heated to the required mold temperature, generally 200 - 250 °C. Heating the runner block aims to ensure that the runner has a relatively high temperature, so that when the aluminum liquid flows through, the temperature loss of the aluminum liquid can be reduced, thereby avoiding phenomena such as cold shut and insufficient pouring caused by excessive temperature drop of the aluminum liquid.

[0034] In this embodiment, after casting is completed in the closed mold state in step S2, cooling water is immediately introduced into the other two left outer mold heat exchange channels and the other two right outer mold heat exchange channels to cool the left runner block and the right runner block. The left outer mold temperature measuring probe is used to detect the temperature of the left runner block, and the right outer mold temperature measuring probe is used to detect the temperature of the right runner block. The measured temperature can be input to the computer control system, and the control system can be used to control the closing of the cooling water to control the cooling temperature of the runner block. Generally, the temperature drop of the runner block can be set to about 50°C. When the measured mold temperature is lower than 50°C, the cooling water is closed. It is also possible to set different temperatures for the temperature of the left runner block and the temperature of the right runner block according to the structural characteristics of specific different piston products. Since multiple heat exchange channels are provided, the runner block can be quickly cooled to the required mold temperature, generally 50°C. It can also be set as required according to the structural characteristics of specific different piston products. Cooling is immediately carried out after casting the runner block, and the purpose is to make the molten aluminum in the runner on the runner block solidify quickly, so that the molten aluminum in the runner solidifies faster than the molten aluminum in the ingate. There is no feeding from the runner to the ingate, and it does not affect the molten aluminum in the ingate. Relying on the characteristics that the wall thickness above the piston head is larger and the wall thickness below is smaller, feeding from top to bottom is achieved.

[0035] In this embodiment, the reason for heating first and then removing the piston blank in step S3 is that: it takes a certain amount of time to heat the mold. By heating first, then removing the piston blank, and then closing the mold, the mold has been heated for a period of time, which can reduce the time for continued heating after closing the mold and avoid waiting for temperature rise after closing the mold. Generally, the set mold temperature value can be reached immediately after closing the mold.

[0036] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An aluminum piston runner, characterized in that: It includes a straight runner, a horizontal runner connected to the straight runner, a blind runner and an entgate connected to the horizontal runner. The entgate is a variable cross-section structure. The blind runner is arranged below the horizontal runner and connected to the blind runner.

2. The aluminum piston runner according to claim 1, characterized in that: The vertical section of the ingates is a T-shaped structure with a narrow lower portion and a wide upper portion.

3. The aluminum piston runner according to claim 2, characterized in that: The minimum wall thickness below the ingrate is Y, the maximum wall thickness above the ingrate is Z, the slope of the ingrate from bottom to top is N, the slope of the ingrate from top to bottom is P, the height of the narrower cross-section part below the T-shaped structure of the ingrate is Q, Y=(0.5~0.9)X, Z=(1.5~2.5)Y, N=(0.5~1.2)M, P=(0.6~1.3)M, Q=(1~1.5)W, wherein X is the minimum wall thickness of the skirt below the piston body, M is the draft angle of the skirt below the piston body, and W is the distance from the end face of the skirt below the piston body to the center of the pin hole.

4. A piston casting mold, comprising an inner mold for forming the inner cavity of a piston body, a guide sleeve for forming the lower end surface of the piston body, a left outer mold and a right outer mold for forming the outer circle of the piston body, and a mold cover for forming the head of the piston body, wherein the guide sleeve is arranged above the inner mold, the mold cover is arranged above the guide sleeve, and the left outer mold and the right outer mold are symmetrically arranged on the left and right sides of the inner mold, characterized in that: The left outer mold and the right outer mold are both provided with a molding cavity for molding the aluminum piston runner as described in claims 1-3.

5. The piston casting mold according to claim 4, characterized in that: The left outer mold includes a left straight runner block, a left outer mold cover plate, a left cross runner block, and a left outer mold base; the right outer mold includes a right straight runner block, a right outer mold cover plate, a right cross runner block, and a right outer mold base; the left straight runner block and the right straight runner block are matched to form the straight runner of the piston runner; the left cross runner block and the right cross runner block are matched to form the cross runner and the blind runner of the piston runner; the left outer mold base and the right outer mold base are matched to form the inner runner of the piston runner; the left cross runner block and the right cross runner block are respectively provided with temperature measuring probes and heat exchange channels; the heat exchange channels are connected with pipe joints for connecting high-temperature heating oil for heating the mold or cooling water for cooling the mold.

6. The piston casting mold according to claim 5, characterized in that: The heat exchange channel is composed of multiple channels arranged in parallel.

7. A piston casting mold casting method according to any one of claims 4 to 6, characterized in that: The steps are as follows: S1, the casting mold is in the mold opening state, the corresponding heat exchange channel is opened, and the left outer mold and the right outer mold are heated respectively. When the corresponding temperature measuring probe detects that the temperature of the two reaches the set value, the mold is closed and the heat exchange channel is closed. At this time, the casting mold is in the pouring state; S2. Aluminum liquid is cast in the mold-closing state. After the casting is completed, the corresponding heat exchange channel is immediately opened for water cooling. When the corresponding temperature measuring probe detects that the cooling temperature reaches the set value, the cooling water is turned off; S3. When the aluminum liquid in the casting mold solidifies, the mold is opened. In the mold open state, the corresponding heat exchange channel is immediately opened again to heat the left outer mold and the right outer mold respectively, and then the piston blank is removed to complete a casting cycle and prepare to enter the next casting cycle.

8. The piston casting mold casting method according to claim 7, characterized in that: The setting temperature of the left outer mold and the right outer mold during heating in the step S1 is 200-250°C.

9. The piston casting mold casting method according to claim 7, characterized in that: The cooling temperature setting value in step S2 is 50±10°C.

10. The piston casting mold casting method according to claim 7, characterized in that: In the steps S1 and S3, heating oil is introduced into the corresponding heat exchange channels to heat the left runner block and the right runner block; in the step S2, cooling water is introduced into the corresponding heat exchange channels to cool the left runner block and the right runner block.

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