Patent Description:
In a machine tool such as a grinder, a temperature of a machining unit is adjusted by flowing a liquid such as a coolant liquid to the machining unit. As a device for supplying such a liquid, there is a liquid circulation device that adjusts a temperature of a liquid while circulating the liquid between the device and the machine tool (for example, refer to <CIT>). The liquid circulation device includes a heat exchanger (cooling coil) and a temperature controller (cryocooler) for adjusting a temperature of the heat exchanger, and adjusts the temperature of the liquid by disposing the heat exchanger in the liquid to be circulated.

Japanese patent document <CIT> discloses a treatment equipment for waste liquid of nonsilver salt photosensitive material, which is equipped with a means for heating the waste liquid to vaporize and concentrate it, a means for cooling and condensing the vapor generated thereby and a means for storing this condensate.

Japanese patent document <CIT> discloses a liquid circulation devise according to the preamble of claims <NUM> and <NUM>.

The liquid that flows to the machining unit of the machine tool includes a metal scarp generated in machining. The metal scarp is usually separated and recovered from the liquid. However, it is difficult to completely recover the metal scarp, and when the heat exchanger is disposed in the liquid without any ingenuity, a problem arises in that the metal scarp in the liquid is deposited on the heat exchanger to lower heat exchange efficiency of the heat exchanger. Further, the heat exchanger is disposed in a tank having a large capacity for storing the liquid. Accordingly, when the heat exchanger is disposed in the tank without any ingenuity, a problem arises in that a liquid that is cooled down around the heat exchanger and a liquid of a high temperature away from the heat exchanger are generated and thus the temperature of the liquid sent to the machine tool is not stable.

An object of the present invention is to provide a liquid circulation device capable of suppressing a deposition of a metal scarp in a liquid on a heat exchanger and uniformly adjusting a temperature of the liquid and a tank.

A liquid circulation device for a machine tool according to the present invention includes a tank which has an introduction portion and a lead-out portion of a liquid, and in which a liquid circulated between the machine tool and the tank is stored; and a heat exchanger disposed in the tank, where the tank has a throttle portion in which a cross-sectional area of a liquid passage between the introduction portion and the lead-out portion is reduced and a first storage portion on the introduction portion side from the throttle portion, and at least a portion of the heat exchanger is disposed in the throttle portion.

Another liquid circulation device for a machine tool according to the present invention includes a first storage portion; another storage portion of which at least a portion is disposed below the first storage portion, and which has a larger liquid capacity than that of the first storage portion; and a heat exchanger disposed inside the first storage portion, where an opening portion through which the first storage portion communicates with the other storage portion is provided at a lower portion of the first storage portion, and at least a portion of the heat exchanger is disposed in the opening portion.

According to the present invention, a liquid circulation device capable of suppressing a deposition of a metal scarp in a liquid on a heat exchanger and uniformly adjusting a temperature of the liquid and a tank can be provided.

<FIG> is a circuit diagram showing a liquid circulation device according to an embodiment of the present invention.

A liquid circulation device <NUM> of the present embodiment is a device that adjusts a temperature of a liquid while circulating the liquid between the liquid circulation device <NUM> and a machine tool <NUM> such as a grinder. As the liquid, various liquids such as a coolant liquid and fresh water can be used. The liquid circulation device <NUM> includes a sludge conveyor <NUM> that receives a liquid that has flowed to a machining unit of the machine tool <NUM>, a separator <NUM> that separates a metal scarp (sludge) from a liquid sucked up from the sludge conveyor <NUM>, a septic tank <NUM> for purifying the liquid separated from the metal scarp by the separator <NUM>, a first filter 16A and a second filter 16B for filtering the liquid sucked up from the septic tank <NUM>, and a temperature control unit <NUM> for introducing the liquid filtered by the first filter 16A or the second filter 16B through a collecting pipe <NUM>. The first filter 16A and the second filter 16B are alternately used in a predetermined cycle, and when one is used in a cycle, the other is washed. The first filter 16A and the second filter 16B may be cleaned by air cleaning equipment <NUM> using compressed air. The temperature control unit <NUM> adjusts the temperature of the introduced liquid. Then, the liquid of which the temperature is adjusted by the temperature control unit <NUM> is sucked up by a pump <NUM> and sent to the machine tool <NUM>. The liquid is forcibly fed between the respective portions by pumps <NUM> to <NUM>. A pressure gauge may be provided at lead-out portions of the pumps <NUM> to <NUM>, and the pressure of the pumps <NUM> to <NUM> may be measured.

<FIG> is a diagram showing a configuration of the temperature control unit. <FIG> is a partially broken side view showing an inside of the temperature control unit <NUM>. <FIG> is a partially broken plan view of the temperature control unit as viewed from above. In <FIG>, a temperature controller <NUM> is indicated by an imaginary line. In <FIG> and <FIG>, a flow of a liquid is indicated by a thick arrow line.

The temperature control unit <NUM> includes a tank <NUM> for storing a liquid, an introduction pipe <NUM> for introducing the liquid, a heat exchanger <NUM> disposed in the liquid, a temperature controller <NUM> for controlling the temperature of the heat exchanger <NUM>, and a lead-out pipe <NUM> for leading out the liquid.

The tank <NUM> is provided with a two-layer structure <NUM> of which a space is partitioned by a horizontal partition plate <NUM> and a second storage portion <NUM> in which a liquid before derivation is stored. The partition plate <NUM> partitions the two-layer structure <NUM> into upper and lower two layers of an upper storage portion 213A and a lower storage portion 213B. The partition plate <NUM> has a through-hole <NUM> at the center, and the upper storage portion 213A and the lower storage portion 213B communicate with each other through the through-hole <NUM>. The upper storage portion 213A may have a flow path (not shown) which returns the liquid to, for example, the septic tank <NUM> when the liquid overflows. The upper storage portion 213A according to one example of the first storage portion according to the present invention. The configuration in which the lower storage portion 213B and the second storage portion <NUM> are combined corresponds to one example of the other storage portion according to the present invention. The capacity of the upper storage portion 213A is smaller than a total capacity of the lower storage portion 213B and the second storage portion <NUM>. The through-hole <NUM> corresponds to one example of a throttle portion and an opening portion according to the present invention.

The heat exchanger <NUM> is disposed above the through-hole <NUM> such that a portion of the heat exchanger <NUM> is located in the through-hole <NUM>. That is, the heat exchanger <NUM> is disposed at a center P0 of the upper storage portion 213A in a horizontal direction. The heat exchanger <NUM> may have a coil-shaped structure. The temperature controller <NUM> is disposed on the tank <NUM> and connected to the heat exchanger <NUM>.

A liquid feed-out port 22a of the introduction pipe <NUM> is disposed in the liquid of the upper storage portion 213A, and at a position separated from the center P0 of the upper storage portion 213A in the horizontal direction, in a horizontal X direction (<FIG> and <FIG>). Further, the feed-out port 22a is disposed in a direction for sending-out the liquid in a horizontal Y direction substantially orthogonal to the X direction (<FIG>). Further, the through-hole <NUM> is disposed in a -Z direction (direction orthogonal to the X direction and the Y direction, that is, a vertical direction) from the center P0 of the upper storage portion 213A (<FIG>). The feed-out port 22a is disposed at a position higher than a bottom of the upper storage portion 213A. A feed-out port 22a of the introduction pipe <NUM> corresponds to one example of an introduction portion according to the present invention.

The second storage portion <NUM> communicates with the lower storage portion 213B, and the liquid of which the temperature is adjusted is sent from the lower storage portion 213B. A suction port 25a of the lead-out pipe <NUM> is disposed in the liquid of the second storage portion <NUM>. The lead-out pipe <NUM> leads out the liquid from the second storage portion <NUM> to the machine tool <NUM> by driving the pump <NUM>. The suction port 25a of the lead-out pipe <NUM> corresponds to one example of a lead-out portion according to the present invention.

The liquid circulation device <NUM> continuously circulates the liquid by driving the pumps <NUM> to <NUM> during an operation of the machine tool <NUM>. That is, the liquid that has flowed to the machining unit of the machine tool <NUM> is first sent to the sludge conveyor <NUM>, and a large amount of metal scarp is recovered. The liquid stored in the sludge conveyor <NUM> is sent to the separator <NUM> and separated from the metal scarp by using a magnetic force. Then, the liquid from which the metal scarp is separated is sent to the septic tank <NUM>. The driving of the pump <NUM> and the driving of the other pump <NUM> are switched in a predetermined cycle. In a certain cycle, the liquid is sucked up from the septic tank <NUM> by the driving of the pump <NUM> and filtered by the first filter 16A. While the liquid is filtered by the first filter 16A, the second filter 16B is cleaned. In another cycle, the liquid is sucked up from the septic tank <NUM> by the driving of the pump <NUM> and filtered by the second filter 16B. While the liquid is filtered by the second filter 16B, the first filter 16A is cleaned. The liquid filtered by the first filter 16A or the second filter 16B is sent to the tank <NUM> of the temperature control unit <NUM> through the introduction pipe <NUM>.

The liquid sent out from the feed-out port 22a of the introduction pipe <NUM> generates a turning flow in the upper storage portion 213A as shown in <FIG> and <FIG> according to the direction and the disposition of the feed-out port 22a described above. For this reason, the liquid in the upper storage portion 213A crosses the heat exchanger <NUM> at a relatively large flow rate and passes through the through-hole <NUM> in the center of the partition plate <NUM> to be sent to the lower storage portion 213B. In addition, a cross-sectional area of the liquid passage between the upper storage portion 213A and the lower storage portion 213B is reduced by the through-hole <NUM>. Thus, a large flow rate of the liquid can be obtained before and after the liquid passage, and the liquid passes through the vicinity of the heat exchanger <NUM> at the large flow rate. When the liquid flows around the heat exchanger <NUM>, heat is exchanged with the heat exchanger <NUM> and the temperature is adjusted (for example, cooling, heating, or both of cooling and heating). However, since the flow rate of the liquid is large around the heat exchanger <NUM>, the metal scarp mixed with the liquid is prevented from being deposited on the heat exchanger <NUM>. Furthermore, since the liquid sent to the lower storage portion 213B also crosses the heat exchanger <NUM>, the liquid in the lower storage portion 213B is adjusted to a uniform temperature.

The liquid of which the temperature is adjusted is sent from the lower storage portion 213B to the second storage portion <NUM> and returned to the machine tool <NUM> by the driving of the pump <NUM>.

As described above, the liquid circulation device <NUM> according to the present embodiment has the partition plate <NUM> and the through-hole <NUM> for reducing the cross-sectional area of the liquid passage in the tank <NUM> of the temperature control unit <NUM>, and a portion of the heat exchanger <NUM> is disposed in the through-hole <NUM>. According to such a configuration, a large flow rate of the liquid can be obtained before and after the through-hole <NUM>. As a result, since the flow rate of the liquid around the heat exchanger <NUM> is increased, the metal scarp contained in the liquid can be prevented from being deposited on the heat exchanger <NUM>. Further, since the liquid passes through the vicinity of the heat exchanger <NUM> equally by disposing the heat exchanger <NUM> such that a portion of the heat exchanger <NUM> is included in the through-hole <NUM>, the temperature of the liquid can be uniformly adjusted. Accordingly, the liquid of which the temperature is efficiently and uniformly adjusted by the heat exchanger <NUM> can be supplied to the machine tool <NUM>.

Further, according to the liquid circulation device <NUM> of the present embodiment, in the tank <NUM> of the temperature control unit <NUM>, the feed-out port 22a of the introduction pipe <NUM> is disposed so as to face the Y direction crossing the X direction in the liquid, and at a position away from the center of the upper storage portion 213A in the X direction. With such a direction and a disposition, the turning flow can be generated in the liquid in the upper storage portion 213A by the liquid fed out from the feed-out port 22a of the introduction pipe <NUM>. Accordingly, the flow rate of the liquid passing through the vicinity of the heat exchanger <NUM> can be made larger by the turning of the liquid. Thereby, the metal scarp contained in the liquid can be fur ther prevented from being deposited on the heat exchanger <NUM>.

Furthermore, in the liquid circulation device <NUM> according to the present embodiment, the through-hole <NUM> of the partition plate <NUM> is disposed at a position in the -Z direction from the center P0 of the upper storage portion 213A. The -Z direction is a direction orthogonal to the X direction in which the feed-out port 22a of the introduction pipe <NUM> is separated from the center P0 and the Y direction in which the liquid is fed out from the feed-out port 22a. According to such a disposition, the liquid turning in the upper storage portion 213A can be sent from the vicinity of the center of the turning to the lower storage portion 213B by the action of the feed-out port 22a. Further, the heat exchanger <NUM> is disposed near the center of the turning. By such a flow of the liquid and the disposition of the heat exchanger <NUM>, it is possible to further enhance the action of suppressing the deposition of the metal scarp on the heat exchanger <NUM> and the action of uniformly adjusting the temperature of the liquid by the heat exchanger <NUM>.

Furthermore, in the liquid circulation device <NUM> according to the present embodiment, the tank <NUM> of the temperature control unit <NUM> has the two-layer structure <NUM> having the upper storage portion 213A and the lower storage portion 213B and adopts the through-hole <NUM> of the partition plate <NUM> as a configuration of reducing the cross-sectional area of the liquid passage. Further, as a configuration of turning the liquid, a configuration for turning the liquid in a direction along a horizontal plane is adopted. According to such a configuration, a disposition space for the tank <NUM> can be reduced, in particular, the area in the horizontal direction where the tank <NUM> is installed can be reduced, and the turning speed of the liquid can be made higher. In addition, a configuration of reducing the cross-sectional area of the liquid passage can be realized with a small number of materials at a low cost.

Furthermore, the liquid circulation device <NUM> according to the present embodiment includes the upper storage portion 213A and another storage portion (lower storage portion 213B and second storage portion <NUM>) having a larger capacity, and the heat exchanger <NUM> is disposed in the upper storage portion 213A having a smaller capacity. The upper storage portion 213A is provided with the through-hole <NUM> communicating with the lower storage portion 213B. In a case where the heat exchanger <NUM> is disposed in a large storage portion for storing the entire liquid for adjusting the temperature at once, a liquid passing far from the heat exchanger <NUM> is generated in the large storage portion, and it is difficult to adjust the temperature of the liquid uniformly. However, by disposing the heat exchanger <NUM> in the upper storage portion 213A having a capacity smaller than the total amount of the liquid for adjusting the temperature as in the above configuration, the liquid passing through the upper storage portion 213A is reduced while being separated from the heat exchanger, and it is possible to adjust the temperature of the liquid uniformly. In addition, in the upper storage portion 213A, the flow rate can be made relatively large due to the small capacity, and the deposition of the metal scarp on the heat exchanger <NUM> can be suppressed. Further, a portion of another storage portion (lower storage portion 213B and second storage portion <NUM>) is located below the upper storage portion 213A, and the through-hole <NUM> for sending the liquid from the upper storage portion 213A to the other storage portion is disposed at a lower portion (for example, a bottom) of the upper storage portion 213A. Accordingly, a liquid flow from above to below is formed in the upper storage portion 213A where the heat exchanger <NUM> is disposed. Thereby, even when metal scarp is contained in the liquid introduced from the introduction pipe <NUM>, it is easy to flow the metal scarp from the through-hole <NUM> to the next storage portion (lower storage portion 213B), and the metal scarp can be prevented from being accumulated in the upper storage portion 213A. Thus, the deposition of the metal scarp on the heat exchanger <NUM> can be further suppressed.

<FIG> is a diagram showing a first modification example of the temperature control unit and <FIG> is a diagram showing a second modification example of the temperature control unit. In <FIG> and <FIG>, the flow of the liquid is indicated by a thick arrow line.

The liquid circulation device <NUM> may be provided with a temperature control unit 20A (<FIG>) of the first modification example or a temperature control unit 20B (<FIG>) of the second modification example instead of the temperature control unit <NUM> described above.

The temperature control unit 20A of the first modification example has an intervening flow path <NUM> interposed between the first storage portion <NUM> and the second storage portion <NUM>, and of which a diameter or a width is made small, as a configuration for reducing the cross-sectional area of the liquid passage in the tank 21A. A portion of the heat exchanger <NUM> is disposed in the intervening flow path <NUM>. The first storage portion <NUM> and the second storage portion <NUM> are vertically arranged side by side. The liquid introduction portion is disposed at a position higher than a bottom of the upper storage portion 213A. The intervening flow path <NUM> is opened to the lower portion of the first storage portion <NUM>, and allows the liquid to pass vertically. A lead-out portion 25A for leading out the liquid is provided at the lower portion of the second storage portion <NUM>. Even with such a configuration, similarly to the temperature control unit <NUM> of the embodiment, it is possible to suppress the deposition of the metal scarp on the heat exchanger <NUM> by increasing the flow rate of the liquid passing through the vicinity of the heat exchanger <NUM>, and it is possible to make the liquid uniformly pass through the vicinity of the heat exchanger <NUM>, and the temperature of the liquid can be uniformly adjusted.

The temperature control unit 20A of the first modification example may be provided with the feed-out port 22a of the introduction pipe <NUM> in the same direction and disposition as in the embodiment as shown in <FIG>. By adding such a configuration, also in the first modification example, it is possible to further suppress the deposition of the metal scarp on the heat exchanger <NUM> by causing the liquid to be turned in the first storage portion <NUM>.

Further, in the temperature control unit 20A of the first modification example, the first storage portion <NUM> has a smaller liquid capacity than the second storage portion <NUM>, and the heat exchanger <NUM> is disposed in the first storage portion <NUM>. The second storage portion <NUM> corresponds to one example of another storage portion according to the present invention, and the intervening flow path <NUM> corresponds to one example of the opening portion according to the present invention. According to such a configuration, since the heat exchanger <NUM> is disposed in the first storage portion <NUM> having a capacity smaller than the total amount of the liquid for adjusting the temperature, the liquid passing through the first storage portion <NUM> is reduced while being separated from the heat exchanger and the temperature of the liquid can be uniformly adjusted. In addition, in the first storage portion <NUM>, the flow rate can be made relatively large due to the small capacity, and the deposition of the metal scarp on the heat exchanger <NUM> can be suppressed.

Further, the second storage portion <NUM> is located below the first storage portion <NUM>, and the intervening flow path <NUM> for sending the liquid from the first storage portion <NUM> to the second storage portion <NUM> is opened at a lower portion (for example, a bottom) of the first storage portion <NUM>. Accordingly, in the first storage portion <NUM> provided with the heat exchanger <NUM>, even when a liquid flow is formed from above to below and the metal scarp is contained in the liquid introduced to the first storage portion <NUM>, it is easy to flow the metal scarp from the intervening flow path <NUM> to the second storage portion <NUM>, and the metal scarp can be prevented from being accumulated in the first storage portion <NUM>. Thus, the deposition of the metal scarp on the heat exchanger <NUM> can be further suppressed.

The temperature control unit 20B of the second modification example has an intervening flow path <NUM> interposed between a first storage portion <NUM> and a second storage portion <NUM>, and of which a diameter or a width is made small, as a configuration for reducing the cross-sectional area of the liquid passage in the tank 21B. A portion of the heat exchanger <NUM> is disposed in the intervening flow path <NUM>. The first storage portion <NUM> and the second storage portion <NUM> are vertically arranged side by side but may be laterally arranged side by side. The intervening flow path <NUM> is provided on the side wall portion of the first storage portion <NUM> so as to flow the liquid in the horizontal direction from the first storage portion <NUM>. The intervening flow path <NUM> may communicate with a top surface portion of the second storage portion <NUM> so as to change the direction in the middle and to flow the liquid in the vertical direction. The second storage portion <NUM> has a lead-out portion 25B for leading out the liquid. Even with such a configuration, similarly to the temperature control unit <NUM> of the embodiment, it is possible to suppress the deposition of the metal scarp on the heat exchanger <NUM> by increasing the flow rate of the liquid passing through the vicinity of the heat exchanger <NUM>. Further, it is possible to make the liquid uniformly pass through the vicinity of the heat exchanger <NUM>, and the temperature of the liquid can be uniformly adjusted.

Also in the temperature control unit 20B of the second modification example, as shown in <FIG>, a feed-out port 22aB of an introduction pipe 22B may be disposed in the liquid, at a position separated from the center of the first storage portion <NUM> in one direction (-Z direction) such that the feed-out port 22aB faces a direction (Y direction) orthogonal to the separated direction. With such a direction and disposition, a flow in which the liquid turns along a Y-Z plane can be generated in the first storage portion <NUM>. The liquid can be moved from the vicinity of the center of the turning of the liquid to the second storage portion <NUM> via the intervening flow path <NUM> by disposing the intervening flow path <NUM> in a direction (-X direction) orthogonal to the Y-Z plane from the center of the first storage section <NUM>. Thus, the deposition of the metal scarp on the heat exchanger <NUM> can be further suppressed by increasing the flow rate of the liquid passing through the vicinity of the heat exchanger <NUM>.

Claim 1:
A liquid circulation device (<NUM>) for a machine tool (<NUM>), comprising:
a tank (<NUM>, 21A, 21B) which has an introduction portion (22a, 22aB) and a lead-out portion (25A, 25B) of a liquid, and in which a liquid circulated between the machine tool (<NUM>) and the tank (<NUM>, 21A, 21B) is stored; and
a heat exchanger (<NUM>) disposed in the tank (<NUM>, 21A, 21B),
wherein the tank (<NUM>, 21A, 21B) has a throttle portion (<NUM>), in which a cross-sectional area of a liquid passage between the introduction portion (22a, 22aB) and the lead-out portion (25A, 25B) is reduced, and
a first storage portion (213A, <NUM>, <NUM>) on the introduction portion (22a, 22aB) side from the throttle portion, characterized in that
at least a portion of the heat exchanger (<NUM>) is disposed in the throttle portion.