DEF quality sensor integrated into a DEF tank with interchangeable control circuit.

Abstract

DEF quality sensor with replaceable control circuit (12), which is integrated into a DEF tank (100) and held in a sensor opening (102) at the bottom of a DEF tank (100), with: a housing (10) comprising a base housing part (14) and a removable cover (16), wherein an outer circumference of the base housing part (14) is held in the sensor opening (102); and the majority of the base housing part (14) is located inside the DEF tank (100) and the removable cover (16) is located outside the DEF tank (100), wherein the control circuit (12) is contained and housed in the removable cover (16), and wherein the removable cover (16) is selectively removable from the housing (10).

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the integration of a diesel exhaust fluid (DEF) quality sensor into the bottom of a DEF tank, wherein the DEF quality sensor also comprises replaceable control electronics. RELATED TECHNOLOGY

[0002] The prior art discloses the immersion of a DEF quality sensor in the DEF fluid of a DEF tank. The DEF quality sensor determines the quality, temperature, and level of the DEF in the DEF tank. In current DEF tank applications, the DEF quality sensor is integrated into the tank, with only half of the sensor exposed to the diesel exhaust fluid. By integrating the DEF sensor into the tank, the DEF sensor is protected from ingress of DEF fluid or DEF fluid components. Integrating the DEF sensor into the DEF tank also protects the DEF sensor from heat exposure. However, if the DEF sensor fails, the entire DEF tank must be replaced. This replacement requires a parts supplier to have sufficient storage space for the entire DEF tank.It would be advantageous if the DEF sensor, which is submerged in the DEF tank, had a replaceable DEF head, which would be a much smaller part than the entire DEF sensor. The replaceable DEF head would be replaced in the event of a failure. However, a replaceable DEF head would compromise the robustness of the sensor, as the DEF sensor's control electronics would be exposed to diesel exhaust fluid and other components of the diesel exhaust fluid.

[0003] US 2020 / 0 182 833 A1 discloses a fluid sensor arrangement in which a quality sensor is provided for the fluid. A quality sensor and a control circuit for evaluating the sensor signals from the quality sensor are located outside the fluid tank.

[0004] DE 10 2012 020 039 A1 discloses a device for storing and delivering an additive for catalytic exhaust gas denitrification in a motor vehicle. This device also includes a quality sensor arranged in a delivery module, which is located inside the storage tank.

[0005] DE 10 2010 024 554 A1 discloses a tank module for a liquid tank. A filter device, which houses a pump device, is arranged in the liquid tank.

[0006] DE 10 2009 029 378 A1 discloses an arrangement for withdrawing fluid from a vehicle tank. It teaches that a first component is to be arranged near the edge of a tank's limiting volume.

[0007] Accordingly, there is a clear need in the art for a DEF quality sensor integrated into a DEF tank with replaceable control circuitry so that the control electronics are not immersed in the diesel exhaust fluid but can be replaced from outside the DEF tank. Summary

[0008] The present invention is a DEF quality sensor integrated into a DEF tank with replaceable control circuitry that allows replacement of the control electronics from outside the DEF tank.

[0009] The DEF quality sensor integrated into a DEF tank with replaceable control circuitry (improved removable DEF quality sensor) preferably includes a housing and control circuitry (or control electronics). The housing preferably includes a base housing portion and a removable cover. A sensor opening is formed in a bottom of the DEF tank wall to receive an outer perimeter of the base housing portion. The base housing portion is sealed to the DEF tank with a suitable sealant. Most of the base housing is located inside the DEF tank. However, a small portion of the base housing's bottom is located outside the DEF tank. The removable cover is located outside the DEF tank. The removable cover contains the control electronics. The removable cover can be attached to the base housing portion using any suitable fastening device or method, such as fasteners or snap-fits.Half of an ultrasonic speed detector is located inside the DEF tank. The remaining part of the ultrasonic speed detector is located outside the DEF tank. The improved, removable DEF quality sensor offers the advantages of reduced storage capacity for spare parts and improved serviceability during repairs. DESCRIPTION OF THE DRAWINGS

[0010] Fig. is a cross-sectional view of an improved removable DEF quality sensor housed in a DEF tank according to the present invention. DETAILED DESCRIPTION

[0011] In Fig., an improved removable DEF quality sensor is shown. The improved removable DEF quality sensor 10 preferably includes a housing 10 and control electronics 12. The housing 10 preferably includes a base housing portion 14 and a removable cover 16. A sensor opening 102 is formed in a bottom of the DEF tank 100 to receive an outer periphery of the base housing portion 14. The base housing portion 14 is sealed to the DEF tank with a suitable sealant 18. The sealant 18 is applied to at least one side of a wall of the DEF tank 100. The sealant 18 must be resistant to diesel exhaust 104, ammonia, and any other components from chemical reactions associated with the degradation of urea. The largest part of the base housing part 14 is located within the DEF tank 100, and a small part of a bottom of the base housing part 14 extends outside a bottom of the DEF tank 100.The removable cover 16 is located outside the DEF tank 100.

[0012] The control electronics 12 preferably includes a thermistor, a piezo-ultrasonic level sensor, and a piezo-ultrasonic quality sensor. Half of the ultrasonic velocity detector is located inside the DEF tank 100, immersed in liquid, and the remaining portion is located outside the DEF tank 100. The removable cover 16 can be attached to the underside of the base housing 14 using any suitable fastening device or method, such as fasteners or snap-fits. The improved removable DEF quality sensor 1 has the advantage of reducing the required storage capacity for spare parts and improving serviceability during repairs.

[0013] While particular embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, it is the aim of the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.

Claims

[1] DEF quality sensor with replaceable control circuitry (12) integrated into a DEF tank (100) and held in a sensor opening (102) at the bottom of a DEF tank (100), comprising: a housing (10) having a base housing portion (14) and a removable cover (16), wherein an outer periphery of the base housing portion (14) is retained in the sensor opening (102); and the majority of the base housing portion (14) is located within the DEF tank (100) and the removable cover (16) is located outside the DEF tank (100), wherein the control circuit (12) is contained and housed in the removable cover (16), wherein the removable cover (16) is selectively removable from the housing (10). [2] DEF quality sensor according to claim 1, wherein a sealant (18) is applied to the outer periphery of the housing (10) and the DEF tank (100). [3] DEF quality sensor with replaceable control circuit (12) according to claim 2, wherein: the sealing agent (18) is resistant to diesel exhaust gases, ammonia and other components from chemical reactions associated with the degradation of urea.

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